Next Article in Journal
Preparation and Corrosion Resistance of Hydrothermal Coatings on LZ91 Mg–Li Alloy
Previous Article in Journal
Simulation and Experimental Study of γ-TiAl Alloy Cutting with scCO2-MQL Based on Modified Heat Transfer Coefficient
Previous Article in Special Issue
Synergistic Disinfection of Photocatalytic Nanomaterials Exposed to UVC, Electricity and Magnetic Fields Against Candida albicans
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Coatings
Volume 15
Issue 10
10.3390/coatings15101216
coatings-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

An Overview of Metallic Abradable Coatings in Gas Turbine Engines

by
Kaue Bertuol
1,*,
Bruno Edu Arendarchuck
1 and
Pantcho Stoyanov
2,*
1
Department of Mechanical, Industrial and Aerospace Engineering, Concordia University, Montreal, QC H3G 1M8, Canada
2
Department of Chemical and Materials Engineering, Concordia University, Montreal, QC H3G 1M8, Canada
*
Authors to whom correspondence should be addressed.
Coatings 2025, 15(10), 1216; https://doi.org/10.3390/coatings15101216
Submission received: 29 August 2025 / Revised: 24 September 2025 / Accepted: 9 October 2025 / Published: 16 October 2025
(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)
Browse Figures
Versions Notes

Abstract

This review presents a comprehensive overview of metallic abradable coatings and the advanced testing methodologies used to evaluate their performance in gas turbine engines. Abradable materials are engineered to act as sacrificial coatings, enabling minimal blade tip wear while maintaining tight clearances between rotating blades and stationary components. Such functionality is critical in aerospace applications, where engines operate at high rotational speeds and across wide temperature ranges. The review examines the principal factors governing the design and selection of metallic-based abradable coatings, including material composition, thermal stability, and microstructural tailoring through the addition of phase modifiers, porosity formers, and solid lubricants. The performance of various metallic matrix materials is also discussed concerning their operational temperature ranges and wear characteristics. Particular attention is given to abradability evaluation methods, emphasizing the need to replicate engine-representative conditions to capture blade–coating interactions, frictional behavior, and wear mechanisms. This review consolidates advances in material compositions, microstructural engineering, and experimental testing, integrating perspectives from materials science, tribology, and methodology to guide the development of next-generation turbine coatings. It specifically addresses the lack of a unified review linking material design, thermal spray processes, and performance evaluation by summarizing key compositions, microstructures, and testing methods.

Graphical Abstract

1. Introduction

Optimizing clearances between rotating blades and stationary casings is a critical determinant of gas turbine engines’ efficiency and operational integrity. Excessive gaps incur aerodynamic leakage and efficiency losses, whereas overly tight tolerances risk damaging blade–casing contacts [1,2]. Abradable coatings provide an engineered solution to this challenge, acting as a sacrificial layer on casing surfaces. Designed to wear back upon blade incursion, thereby preserving optimal clearances while minimizing blade damage, significantly enhancing engine efficiency and operational safety across diverse flight regimes and temperatures [3,4,5].
Since the early years, the use of sacrificial coatings has challenged the engineering process. Different coating systems have been developed in recent years or are being evaluated at present [6]. The deployment of abradable coatings, particularly within aero-engine applications, necessitates a complex balance of often antagonistic material properties under demanding thermomechanical conditions [7,8]. It works together with the blade, as mentioned by DeMasi-Marci & Gupta [9], the blade tips, spinning at high speeds, must function as an efficient cutting tool. This is essential to prevent damage to the seal or the blades themselves, as ineffective cutting can lead to blade fracture. Achieving this balance necessitates sophisticated composite microstructures, typically comprising a matrix for strength and environmental resistance, combined with solid lubricants or fugitive phases to promote controlled fracture and crack propagation, and often deliberate porosity to further enhance abradability [10,11,12]. However, this microstructural complexity, coupled with the influence of thermal spray deposition processes, makes predicting in-service performance from fundamental material properties difficult.
Consequently, abradability evaluation under representative engine conditions is indispensable. Conventional tribological tests lack the high-speed, transient thermomechanical fidelity required to reproduce blade–coating rub events, which involve rapid frictional heating, evolving stress fields, and potential adhesive transfer [13]. To bridge this gap, specialized high-speed abradable test rigs have been developed by leading research institutions and industry partners, such as Oerlikon Metco [14], NRC Canada [11], the University of Sheffield [15], and BGRIMM [16]. These rigs have emerged as a solution to simplify and economize evaluation processes [1,17]. It fundamentally works by rotating a simulated turbine blade at relevant tip speeds against a stationary abradable specimen while precisely controlling key inputs: blade speed, incursion rate, incursion depth, and operating temperature. Sophisticated instrumentation captures critical outputs such as tangential and normal reaction forces, rubbing temperatures, blade wear, and adhesive transfer, alongside indirect observations such as debris morphology and surface topology.
The precise control and measurement offered by these rigs are essential for generating reliable, application-relevant data on wear mechanisms, frictional response, and overall coating performance, enabling the validation and optimization of next-generation metallic abradable systems for increasingly demanding aerospace applications [3,18].
Based on this current situation, this review addresses the lack of a systematic synthesis connecting material design, thermal spray processing, and high-speed abradability testing. The paper is structured in sections, starting with an overall concept of abradable materials. The second discusses the deposition process, focused on the thermal spray process, followed by a discussion of material design strategies for metallic abradable coatings. In the Section 5, the study then explores abradability testing methodologies and addresses the scientific basis of abradability evaluation, highlighting the limitations of conventional tribological approaches and the role of advanced high-speed test rigs in producing engine-representative experimental data.

2. Abradable Materials

Abradable materials are engineered sacrificial layers primarily used in gas turbine engines to manage clearances between rotating and stationary components. Their core function is to reduce air leakage by enabling tight blade tip clearances, which improves engine efficiency, reduces fuel consumption, and prevents structural damage during transient blade-shroud contacts [3,19,20]. The materials are designed to be selectively worn away during blade incursion while preserving the structural integrity of the rotating component, making them an essential part of modern turbomachinery sealing strategies [3,10,21].
Figure 1 illustrates a representative interaction between rotating blades and the abradable material applied to the engine casing. The rightmost image shows a cross-sectional view of the resulting wear track, highlighting the controlled sacrificial wear of the abradable. This behavior is critically dependent on the material’s engineered properties, which must ensure predictable wear without compromising blade integrity [22].
From a design point of view, the successful performance of an abradable system relies on a complex balance of thermomechanical properties, tribological behavior, and microstructural design. According to industry standards and recent research [10,23,24], abradable materials should meet the following performance criteria:
  • Be readily abradable but mechanically stable;
  • Exhibit corrosion and oxidation resistance;
  • Have a low coefficient of friction;
  • Resist erosion from gas flows and solid particles;
  • Present a consistent microstructure;
  • Minimize wear of blade tips or knife edges;
  • Avoid material transfer between the blade and the abradable;
  • Disintegrate into fine particles, large debris can potentially damage the engine;
  • The rubbing process should break the bond between particles rather than melting them;
  • Maintain a smooth post-wear surface to reduce aerodynamic losses.

2.1. Classification

To fulfill these diverse and often conflicting requirements, abradable materials are typically categorized into polymeric, metallic, and ceramic systems based on their operational temperature range. Usually, combinations of these materials are used to create composite abradables that leverage the advantages of each class. The selection of a specific material category is primarily determined by the intended engine zone and its associated operating conditions [10,25]. Table 1 provides a classification and representative examples of the metallic, polymeric, and ceramic abradable seals.

2.1.1. Polymer Materials

Polymeric abradables are primarily employed in low-temperature regions of aircraft engines, typically below 250 °C, such as in auxiliary power units (APUs), fan modules, and in some cases in the LPC stages [10,27]. These materials are based on thermoplastic or thermosetting polymers, often reinforced or blended with solid lubricants and fillers to optimize tribological and thermal properties. Common examples include epoxy resins, polyetheretherketone (PEEK), polytetrafluoroethylene PTFE), Ultra-High-Molecular-Weight Polyethylene (UHMW-PE), Polyamideimide (PAI), and silicon-based materials [10,25,30]. Although their thermal stability is limited compared to metallic or ceramic counterparts, polymeric abradables are valued for their low hardness, excellent conformability, ease of repair, and capacity to minimize damage to blade tips during contact events [25,27].

2.1.2. Ceramic Materials

On the other hand, ceramic abradables are employed in the hottest regions of gas turbine engines (above 760 °C), including turbine shrouds and high-pressure stages [34,38]. They are typically based on partially stabilized zirconia (PSZ), such as yttria-stabilized zirconia (YSZ), which offers low thermal conductivity, excellent high-temperature mechanical strength, and robust resistance to oxidation and erosion [39,40]. However, the inherent brittleness and elevated hardness of these ceramics can exacerbate blade wear upon contact [41]. To mitigate this, ceramic abradables are often formulated with a release agent that lowers the friction coefficient of the coating and a fugitive polymer phase that burns out and generates controlled porosity to improve abradability [3,34].

2.1.3. Metallic Materials

Metallic abradables are used in moderate-temperature environments (typically 250–750 °C), such as in the LPC and high-pressure compressors (HPC) stages of aircraft engines [42,43]. These materials generally use soft metals in the main matrix, combined often with a polymeric phase and solid lubricants (e.g., polyester, graphite, or hBN) to enhance their abradability properties [3,43]. When compared to polymeric and ceramic abradables, metallic abradables offer a favorable balance between structural strength and ease of wear during blade interaction [3,25].

2.2. Manufacturing Process

Due to the multifaceted and often conflicting property requirements, the manufacturing method used to produce each class of abradable materials plays a critical role in determining their overall performance and reliability in service. The selection of fabrication technique not only affects the microstructure and mechanical behavior but also governs the material’s consistency, manufacturing repeatability, and scalability for industrial use. Table 2 presents a summary of some of the processes and some main characteristics achieved by the material using this methodology.
For polymeric abradables, common manufacturing techniques include conventional polymer processing methods such as compression molding [27], casting [42,46], and more recently, additive manufacturing (3D printing) [47]. These methods offer good flexibility in terms of geometrical design and can incorporate lubricants or fillers to enhance abradability properties.
In contrast, ceramic abradables are typically fabricated using powder-based methods (e.g., additive manufacturing [48], sintering [49]), these processes are effective at achieving dense microstructures and high-temperature phase stability but often lack the level of microstructural tunability required for abradability, such as controlled pore networks or embedded dislocator phases. To address this, plasma spraying of ceramic blends with engineered porosity has gained attention in recent years, especially for applications demanding thermal barrier-like behavior combined with controlled erosion resistance [34,50].
For metallic-based abradables, the choice of fabrication technique significantly influences performance. While some fabrication methods overlap with those used in polymeric and ceramic systems, the most widely adopted method for metallic abradables is thermal spraying. Given the critical role that thermal spray processes play in manufacturing and optimizing metallic abradable systems, the following dedicated section aims to explore in detail the fundamentals of thermal spray technology, its parameters, and influence on coating properties.

3. Thermal Spray Deposition Process

Thermal spraying is a surface engineering technique in which a feedstock material, typically in the form of powder, wire, or suspension, is heated and accelerated toward a substrate, forming a protective or functional coating. This process relies on the plastic deformation and solidification of high-velocity, high-temperature particles upon impact, creating a dense, layered coating structure [51]. Nearly any material that can be melted without decomposition can be thermally sprayed [10,52]. The heat source may be derived from combustion or an electric arc [53]. The coating is then formed by a series of overlapping layers in a lamellar shape, arising from the scattering of the molten and semi-molten particles [53]. Figure 2 presents a simplified schematic of the thermal spraying process.
The primary objective of thermal spray coatings is to enhance the surface properties of components while protecting the underlying substrate. Depending on the application, coatings can be tailored to improve wear resistance, corrosion protection, thermal insulation, or extend fatigue life. In the case of abradable coatings, the aim is to enable controlled sacrificial wear to optimize sealing performance in turbomachinery. Achieving the desired coating characteristics depends strongly on the selection of process parameters, particularly flame temperature and particle velocity, which influence particle melting, adhesion, and microstructural development [54,55,56,57].
Coatings produced by thermal spray processes are usually highly anisotropic, having a layered and lamellar structure. The shape of these individual deposits and their interaction with each other determines much of the coating properties, including inter-lamellar pores caused by rapid solidification, very fine voids formed by incomplete inter-splat contact, and cracks generated by thermal stresses [10]. Therefore, porosity, cohesion, and oxide presence are good examples of coating properties that can be controlled by the selection of spraying parameters [54,58].
There are several advantages of using the thermal spray approach. The main ones are versatility in terms of materials (both coating and substrate) and relatively low operating costs [55,59]. Among the various methods available, key techniques include Atmospheric Plasma Spray (APS), Cold Spray (CS), Arc Spraying (Electric Arc AS), Flame Spraying (Flame), High-Velocity Oxy-Fuel (HVOF) and High-Velocity Air–Fuel (HVAF), as highlighted by Pawlowski [51].
The fundamental differences between these processes lie in the interaction of the gas flow with the feedstock particles, specifically the temperature and velocity conditions, which govern the particle state during deposition [60]. These dynamics play a critical role in defining the coating microstructure and performance. Figure 3a presents a schematic classification of the main thermal spray processes, categorizing them by their energy source. In the processes, Figure 3b outlines the typical operational ranges of each spraying technique in terms of particle temperature, velocity, and feedstock size, illustrating their suitability for different material systems and coating requirements.

3.1. Atmospheric Plasma Spray (APS)

The APS technique is distinguished by its high versatility, enabling the deposition of a broad range of materials across varied temperatures, particle velocities, and powder size distributions. In APS, particles typically can reach velocities of up to 300 m/s and temperatures exceeding 30,000 K [55,63,64,65]. This flexibility makes APS particularly suitable for processing complex material systems, including metallic–polymer composites. Several studies [16,66,67] have employed APS to fabricate such composites, leveraging its capability to accommodate wide particle size ranges (e.g., abradable feedstocks between 11 and 176 µm [68]) while maintaining effective deposition and microstructural control.
In this technique, an electric arc is formed between a tungsten electrode and a copper anode, which heats and ionizes the gases, usually argon, helium, nitrogen, hydrogen, or a mixture, to create a plasma flame. As the gases pass through the arc, they are heated and expand axially and radially, thus being accelerated through the outlet nozzle. The powder is then injected into the plasma flame, where the particles are fused and sprayed onto the substrate [55,63]. The basic concept of how the plasma spray process works can be seen in Figure 4.
Plasma spray technology enables the fabrication of coatings with a broad range of thicknesses, offering adaptability to meet diverse industrial requirements. For instance, studies by Liu et al. [16] and Jech et al. [69] demonstrated the successful deposition of AlSi–Polyester composite coatings with thicknesses ranging from several micrometers to a few millimeters. This level of control is particularly advantageous in applications requiring tailored layer dimensions for mechanical or thermal performance. A prominent example is found in gas turbine abradable coatings, where thick deposits, often exceeding 3 mm [63], are necessary to ensure sufficient material for blade incursion without compromising structural integrity or sealing efficiency.
The ability to apply such complex coatings while maintaining microstructural consistency underscores the value of thermal spray processes in critical aerospace components. Furthermore, from a materials design perspective, precise control over thermal spray parameters, and resulting coating properties is essential for achieving the desired balance of performance characteristics. In the context of this study on abradables, the following section turns to how these engineered coatings are composed and crucial for gas turbine applications.

4. Metallic-Based Abradable Coatings

Metallic abradable coatings play a pivotal role in gas turbine compressor applications, where precise clearance control between rotating blades and stationary casings is essential for maximizing efficiency and preventing damage during transient incursions. However, formulating a coating that simultaneously provides high abradability along with robust erosion and corrosion resistance remains a significant materials engineering challenge [3,70,71,72].

4.1. Coatings Requirements

As presented in Section 2, the coating requires several demanding properties, such as being soft enough to be removed without damaging the blades or other engine components, while also maintaining strong bonding strength and resistance to solid particle erosion and corrosion. Integrating these competing, and often opposing, properties within a single material system is particularly challenging and is typically addressed through the development of composite materials. Metallic–polymer composite materials stand out as promising abradable materials [7,10,72,73,74].
The design of abradables faces a fundamental paradox: while high porosity is essential for achieving excellent abradability and protecting blade tips, it simultaneously compromises the coating’s performance in other critical areas. This high void content significantly reduces the material’s resistance to high-velocity particle erosion and thermal flow. Furthermore, it creates easy diffusion pathways for corrosive agents, leading to material degradation and premature failure. Although high porosity offers superior thermal insulation, it can also heighten the risk of cracking from thermal shock. Consequently, the central challenge in developing these coatings is to achieve a precise balance between abradability and crucial properties such as erosion resistance, corrosion resistance, and thermal stability, all while maintaining the necessary structural integrity for demanding high-temperature service [29].
Figure 5 presents a schematic of the key factors to consider in the selection and development of an abradable coating, where properties such as hardness and interparticle bonding strength often stand in contrast when optimizing for erosion resistance versus abradability. Enhanced erosion resistance requires higher hardness and stronger interparticle bonding, whereas effective abradability favors lower hardness and weaker bonding to facilitate controlled material removal, as indicated by the arrows in the figure.
To satisfy this challenging set of criteria, metallic-based abradable coatings are typically formulated using a combination of a metallic matrix, a solid lubricant or dislocator phase, and a controlled level of porosity [10,11,12]. Each component serves a critical function. The metallic matrix, commonly composed of aluminum–silicon, nickel, cobalt, or copper alloys, provides structural integrity and contributes to the overall strength and wear resistance of the coating [75,76]. Embedded within this matrix, the solid lubricant or dislocator phase facilitates crack initiation and propagation, introducing inherent weakness that ensures fine and controlled wear debris [10,12,20]. Typical examples of such phases include hexagonal boron nitride (hBN), molybdenum disulphide (MoS2), and graphite [77,78,79,80]. These phases generally do not chemically bond with the metallic matrix [10], helping ensure that the resulting debris remains sufficiently small to avoid downstream damage.
In addition to compositional design, porosity is often deliberately introduced through feedstock engineering or by adjusting thermal spray parameters. While increased porosity, generally governed by the volume fraction and size of pores, tends to improve abradability, it often reduces erosion resistance, thereby requiring careful optimization [10,11]. For instance, Liu et al. [16] demonstrated that the volume of filler material plays a significant role in determining the abradability of aluminum-based coatings. Beyond porosity control, polymeric additives are also employed to reduce stress propagation during blade–coating interactions [81]. Stringer and Marshall [66] further emphasized that such additives help limit damage to the structural matrix phase, supporting coating integrity under service conditions. Figure 6 presents a typical coating configuration of a metallic-based abradable coating incorporating polymer filler material, illustrated through macro photography, micro-CT imaging, and SEM analysis. Figure 6 highlights the distribution of filler material, the porosity network, and the underlying bond coat layer applied to enhance adhesion to the substrate.
A well-established metallic-based abradable coating system is AlSi incorporated with 40 wt.% polyester [72,82,83], in which the polyester serves as a fugitive filler phase. The polyester lowers the overall coating hardness and promotes controlled porosity, without significantly compromising adhesion strength [17]. Figure 7 presents cross-sectional micrographs of AlSi coatings containing different polyester contents, illustrating the inverse correlation between filler concentration and HR15Y hardness. In the images, the lighter regions correspond to the aluminum–silicon metallic matrix, while the darker regions indicate the presence of the polymer filler [43].
Moreover, the thermomechanical stability of these coatings remains a critical concern. Polyester additives improve abradability by absorbing mechanical energy, they are prone to softening at elevated temperatures, which can reduce performance [85,86]. Conversely, hBN, a solid lubricant, improves thermal stability and lubrication but may introduce microstructural heterogeneities that influence wear behavior [35,80]. Previous studies [87,88,89] have highlighted temperature-driven changes in coating behavior, including increased polymer softening, shifts from ductile-dominant to mixed or brittle wear modes, and enhanced adhesive transfer to the blade at higher temperatures.
This complex interplay between material composition, microstructure, and thermomechanical behavior highlights the need for a systematic understanding of how different metallic abradable coatings perform across varying temperature regimes inside the gas turbine engines [90].

4.2. Temperature-Based Categorization of Metallic Abradable Coatings

Given the highly heterogeneous composite structure of abradable coatings [81] and the inherent complexity of thermal spray processes [91], the investigation, comparison, and development of new coatings remain challenging, particularly when tailored to distinct application environments. In aero-engines, abradable coatings are employed at various locations, each subjected to specific and often demanding temperature conditions. From this perspective, a practical and widely adopted classification approach is to categorize these coatings based on their temperature capability [92]. Figure 8 illustrates the typical temperature regimes encountered in jet engines, along with the corresponding abradable materials commonly used at each stage [10,24].
Below 450 °C (LPC zones), usually AlSi-based alloys offer an optimal balance between abradability and erosion resistance [1,20,38]. In the intermediate temperature range of 450 °C to 750 °C, corresponding to high-pressure compressor (HPC) regions, cobalt-based, copper-based, nickel-based, and M-CrAlY alloys are commonly employed due to their favorable combination of corrosion resistance, lubricity, and erosion resistance. For high-temperature environments such as high-pressure turbines (HPT), yttria-stabilized zirconia (YSZ) is the conventional abradable material of choice [1,20]. A summary of traditional metallic abradable coatings is presented in Table 3, highlighting their main chemical compositions, operating temperature ranges, key performance attributes, and relevant references.
As detailed in Table 3, metallic-based abradable coatings cover a wide range of compositions and operating temperature regimes. These coatings are intrinsically complex due to their heterogeneous composite structures, often comprising multiple phases and engineered porosity, introducing microstructural inhomogeneities that significantly influence wear behavior [81]. This structural complexity poses substantial challenges for understanding wear mechanisms and correlating microstructural features with performance metrics.
The selection of abradable coating material is fundamentally governed by the thermophysical requirements of each specific engine region. The matrix generally provides the coating strength and resistance to the environment while ensuring that the material can be preferentially worn to prevent excessive blade wear. Al and Cu alloys are typically utilized as the matrix material, and due to their relatively lower melting temperatures, they are generally employed in the low-temperature zones of the low-pressure compressor (LPC) [10]. These alloys are specifically designed to balance erosion resistance with excellent abradability.
As we move towards the hotter sections of the engine, such as the high-pressure compressor (HPC) and turbine (HPT), more advanced materials are required. Here, Co- and Ni-based alloys and ceramic abradables are applied to support the hotter temperatures, with the choice of matrix being a function of the specific region’s thermal load. Under high-temperature service conditions (≥1300 °C), however, conventional metal-based materials increasingly exhibit service performance limitations due to their insufficient thermal stability [29].
Regardless of the matrix material, a critical component is the addition of solid lubricants or dislocator phases, such as graphite and boron nitride, which are among the most commonly used dislocator materials. These function as an initiation and propagation route for cracks, providing the coating with an inherent weakness while ensuring that the abradable debris is sufficiently small so it cannot block cooling channels or instigate downstream erosion [10,31].
Moreover, the thermal spray deposition processes used to manufacture these coatings introduce additional variables, including residual stresses [110], splat morphology, and inter-splat bonding characteristics [111] which further complicate performance assessment. Standardized evaluation methods are difficult to apply universally, as the tribological behavior of these materials is highly dependent on their specific mechanical configurations. Given these intricacies, the following section is therefore dedicated to briefly reviewing and analyzing the primary techniques employed for evaluating the performance of abradable coatings, with a focus on abradability evaluation.

5. Abradability Evaluation

The physical interaction between rotating blade tips and abradable coatings during rub events presents a highly complex, transient thermomechanical phenomenon. This complexity arises primarily from the contact between dissimilar materials, including composites, operating under the harsh conditions characteristic of aerospace applications, such as high rotational speeds and elevated temperatures [19,112].

5.1. Conventional Tribological Tests and Limitations

Although existing friction models [113,114] offer first-order approximations of contact forces and frictional heating during rubbing events, they are insufficient for capturing the full spectrum of thermomechanical interactions, particularly the rapid temporal and spatial variations in temperature, stress, and material response. As a result, experimental validation through physical testing remains indispensable for accurate characterization.
During blade–abradable interactions, the high tip velocities generate significant transient heat, leading to complex distributions of frictional forces, such as tangential and normal reactive forces at the interface. These forces are strongly influenced by localized, rapidly evolving thermal fields that alter the mechanical behavior of both the blade material and the abradable coating. The resulting variations in hardness, strength, and ductility further complicate the force dynamics. Additionally, incursion-induced mechanical instabilities in the blade are poorly understood and represent an area of ongoing research [23,37,86].
Conventional methods, such as the Scratch, Impact test, Scratch hardness, and Sliding wear tests, are characterized by their ease of implementation and cost-effectiveness. These techniques are valuable for initial material screening and for providing fundamental tribological data, often by measuring mass loss or wear rate under controlled conditions. However, a significant shortcoming is their limited capacity to replicate actual operational environments. These methods fail to incorporate the high-speed rubbing, elevated temperatures, and specific contact kinematics of a gas turbine engine, leading to a substantial deviation from real-world performance [29].
To overcome these limitations, a multifaceted assessment strategy has emerged as a standard practice. Abradability evaluation is employed using specialized test rigs capable of simulating engine-representative conditions. These tests provide critical insights into coating wear mechanisms, blade degradation, frictional responses, and potential material transfer phenomena at the blade tip [14,81,115]. A schematic representation of the rubbing process in conventional abradability testing is shown in Figure 9.
According to Xue et al. [67], and Stringer and Marshall [66], identifying wear mechanisms and blade wear in different operating conditions, as well as determining frictional heating and rubbing reaction forces, are crucial in validating all abradable systems. Similar studies also support these findings [11,116]. Post-rubbing surface analysis of the coating is commonly performed to assess abradability and associated blade wear. To support such evaluations, various studies have designed dedicated rigs for assessing abradable materials [14,18,23,66,100,115,117]. A widely adopted approach is the use of high-speed abradable test rigs, which enable precise control over the main parameters such as blade speed (up to 500 m/s), incursion rate (1–2000 µm/s), incursion depth (typically up to 2 mm), and operating temperature (up to 1200 °C).
Several studies have reported quantitative performance outcomes for metallic abradables. For instance, AlSi-based coatings have been widely investigated, where different filler additions (e.g., polyester, hBN, or metallic reinforcements) were shown to influence wear track morphology, groove depth, and surface roughness after rubbing [16,88,90,92].

5.2. High-Speed Abradable Test Rigs

Compared to full-scale engine tests, high-speed abradable rigs significantly reduce testing time and cost, while still providing an accurate assessment of coating abradability [118]. The apparatus is designed to replicate, at a reduced scale, the blade–casing interaction characteristic of aero-engine operation. It models the operational environment between a rotating compressor blade and a stationary abradable seal [17,100].
The typical setup includes a dummy blade mounted on a rotating disk and an abradable specimen under investigation. An incursion motion is induced using a stepper motor, providing the interaction between the abradable and the dummy blade. Some rigs are equipped with a heating apparatus to replicate the real-engine operating temperatures. Various sensors can be employed to gather pertinent data, including reaction forces, rubbing temperatures, incursion depth, and disk speed [14,81]. Figure 10a shows a schematic of a high-speed abradable test apparatus developed by Sulzer Metco [14], while Figure 10b displays typical post-rubbing surface features observed after testing.
Abradable test rigs are designed to offer a broad range of configurable input parameters. Key input parameters include: blade rotational speed, incursion rate, incursion depth, abradable materials, and operating temperature. These variables allow for flexible test scenarios tailored to specific material evaluations or application targets. Table 4 summarizes the main inputs and outputs typically evaluated on abradability assessments by abradable test rigs, categorized by qualitative and quantitative analysis. The outputs provide valuable data to assess the mechanical and thermal interactions between the blade and abradable material. Moreover, post-test analysis is enabled through the removal of specimens from the rig, allowing for a thorough inspection of the abradable degradation, blade wear, and material transfer. Additional laboratory evaluations, such as surface roughness measurements, wear mechanism identification, and debris characterization, can offer deeper insights into understanding and optimizing the performance of turbine blade systems.
Having the data from abradability tests, coatings are typically favored when they exhibit low reaction forces and minimal frictional heating during incursion. High reaction forces are generally undesirable, as they are correlated with increased blade wear, surface damage, and potential structural instabilities. They are often associated with a rougher scar appearance on the abradable surface [23], increased adhesive material transfer to the blade tip [67], and more pronounced wear features such as grooves or micro-cracks [119].
In summary, as discussed by Wang et al. [29], the adoption of customized test rig methodologies has become increasingly prevalent for evaluating the abradability of aerospace seal coatings primarily because they provide a high degree of fidelity to actual operating conditions. However, the application of these comprehensive tests is sometimes limited by their high cost and the lack of standardized criteria for wear evaluation, which could be addressed by the research area by the use of abradable test rigs with a low velocity [13].
Reliable performance assessment requires recognizing the limitations of both conventional tribological tests and abradability rigs. While conventional methods remain useful for initial pre-screening, abradability rigs provide engine-representative data and capture key outputs. A robust evaluation of ASC performance necessitates a hybrid approach. By combining both evaluation stages, researchers can comprehensively characterize a coating’s performance and address the multifaceted demands of modern aerospace applications, supporting the design and validation of next-generation metallic abradable coatings.

6. Conclusions

This review has provided a comprehensive assessment of metallic abradable coatings, thermal spray deposition processes, and experimental evaluation methodologies relevant to aerospace turbine engines. Particular emphasis was placed on the interplay between material design, microstructural engineering, and high-speed abradability testing in ensuring reliable performance under operationally demanding conditions, linking with some main points:
  • The abradability of metallic coatings is critically influenced by the optimization of coating composition, engineered microstructure, and thermal stability, which must be tailored to specific operational temperature regimes.
  • Distinct metallic matrix systems, including AlSi, Ni, Co, and Cu-based alloys, demonstrate performance advantages that are strongly dependent on their operational temperature and intended abradability characteristics.
  • High-speed abradable test rigs provide a controlled and instrumented environment for reproducing engine-representative blade–coating interactions, enabling the quantitative assessment of reaction forces, wear mechanisms, and coating degradation.
  • The integration of materials science principles, tribological insights, and advanced experimental methodologies constitutes a robust framework for the development, validation, and optimization of next-generation abradable coatings.
Prospective research avenues include:
  • The design and implementation of multi-layer or functionally graded abradable coatings to extend operational performance across wider temperature ranges.
  • The application of computational modeling and machine learning approaches to enable predictive material design and process optimization.

Author Contributions

K.B.—Writing—original draft, Writing—review and editing, Methodology; B.E.A.—Methodology, Writing—review and editing; P.S.—Project administration, Resources. Supervision, Validation, Writing—review and editing. All authors have read and agreed to the published version of the manuscript.

Funding

This work was funded by the Consortium for Research and Innovation in Aerospace in Québec (CRIAQ).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Acknowledgments

The authors would like to thank Concordia University for the facilities, the Consortium for Research and Innovation in Aerospace in Québec (CRIAQ), Canada’s leading innovation organization Mitacs.

Conflicts of Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

References

  1. Dorfman, M.R.; Dwivedi, G.; Dambra, C.; Wilson, S. Perspective: Challenges in the Aerospace Marketplace and Growth Opportunities for Thermal Spray. J. Therm. Spray Technol. 2022, 31, 672–684. [Google Scholar] [CrossRef]
  2. Rathmann, U.; Olmes, S.; Simeon, A. Sealing Technology: Rub Test Rig for Abrasive/Abradable Systems. In Proceedings of the ASME Turbo Expo 2007: Power for Land, Sea, and Air, Montreal, QC, Canada, 14–17 May 2007; American Society of Mechanical Engineers Digital Collection: New York, NY, USA, 2009; pp. 223–228. [Google Scholar] [CrossRef]
  3. Huang, J.; Cao, X.; Chen, W.; Guo, X.; Li, M.; Wang, W.; Dong, S.; Liu, L.; Chen, M. A comprehensive review of thermally sprayed abradable sealing coatings: Focusing on abradability. Chin. J. Aeronaut. 2024, 37, 1–25. [Google Scholar] [CrossRef]
  4. Ghasripoor, F.; Schmid, R.K.; Dorfman, M.R.; Russo, L. A Review of Clearance Control Wear Mechanisms for Low Temperature Aluminium Silicon Alloys. In Proceedings of the ITSC 1998, Nice, France, 25–29 May 1998; pp. 139–144. [Google Scholar] [CrossRef]
  5. Smiarowski, M.W.; Leo, R.; Scholten, C.; Blake, J. Steam Turbine Modernization Solutions Provide a Wide Spectrum of Options to Improve Performance; Siemens Power Generation: Munich, Germany, 2005. [Google Scholar]
  6. Borel, M.O.; Nicoll, A.R.; Schläpfer, H.W.; Schmid, R.K. The wear mechanisms occurring in abradable seals of gas turbines. Surf. Coat. Technol. 1989, 39–40, 117–126. [Google Scholar] [CrossRef]
  7. Bounazef, M.; Guessasma, S.; Ait Saadi, B. The wear, deterioration and transformation phenomena of abradable coating BN–SiAl–bounding organic element, caused by the friction between the blades and the turbine casing. Mater. Lett. 2004, 58, 3375–3380. [Google Scholar] [CrossRef]
  8. Hardwicke, C.U.; Lau, Y.-C. Advances in Thermal Spray Coatings for Gas Turbines and Energy Generation: A Review. J. Therm. Spray Technol. 2013, 22, 564–576. [Google Scholar] [CrossRef]
  9. DeMasi-Marcin, J.T.; Gupta, D.K. Protective coatings in the gas turbine engine. Surf. Coat. Technol. 1994, 68–69, 1–9. [Google Scholar] [CrossRef]
  10. Mohammad, F.; Mudasar, M.; Kashif, A. Criteria for Abradable Coatings to Enhance the Performance of Gas Turbine Engines. J. Mate Sci. Metall. 2021, 2, 101. [Google Scholar]
  11. Irissou, E.; Dadouche, A.; Lima, R.S. Tribological Characterization of Plasma-Sprayed CoNiCrAlY-BN Abradable Coatings. J. Therm. Spray Technol. 2014, 23, 252–261. [Google Scholar] [CrossRef]
  12. Fois, N.; Watson, M.; Marshall, M. The influence of material properties on the wear of abradable materials. Proc. Inst. Mech. Eng. Part J J. Eng. Tribol. 2017, 231, 240–253. [Google Scholar] [CrossRef]
  13. Bertuol, K.; Arendarchuck, B.E.; Rivadeneira, F.R.E.; de Castilho, B.C.N.M.; Moreau, C.; Stoyanov, P. Design and Development of Cost-Effective Equipment for Tribological Evaluation of Thermally Sprayed Abradable Coatings. J. Therm. Spray Technol. 2024, 34, 852–865. [Google Scholar] [CrossRef]
  14. Metco, O. Rapid Validation of Turbomachinery Abradable Systems Using Oerlikon Metco’s Rub-Test Facility. In SF-0029.0—Abradable Testing; Oerlikon: Zürich, Switzerland, 2020. [Google Scholar]
  15. Rahimov, E.; Watson, M.; Hadjisoteriou, A.; Marshall, M. Investigation of wear mechanisms in AlSi-polyester abradable—Ti(6Al4V) blade contacts using stroboscopic imaging. Wear 2022, 494–495, 204207. [Google Scholar] [CrossRef]
  16. Liu, J.; Yu, Y.; Liu, T.; Cheng, X.; Shen, J.; Li, C. The Influence of Composition and Microstructure on the Abradability of Aluminum-Based Abradable Coatings. J. Therm. Spray Technol. 2017, 26, 1095–1103. [Google Scholar] [CrossRef]
  17. Metco, O. Thermally sprayed abradable coating technology for sealing in gas turbines. In Proceedings of the 6th International Conference “The Future of Gas Turbine Technology”, Brussels, Belgium, 17–18 October 2012. [Google Scholar]
  18. Lu, Q.Y.; Shen, J.; Yu, Y.G.; Ren, X.J.; Xuan, H.J.; Liu, T. Progress on Facilities and Methodology to Evaluate Abradable Seal Coatings. Adv. Mater. Res. 2013, 690–693, 1992–1998. [Google Scholar] [CrossRef]
  19. Berthoul, B.; Batailly, A.; Legrand, M.; Stainier, L.; Cartraud, P. Abradable Coating Removal in Turbomachines: A Macroscopic Approach Accounting for Several Wear Mechanisms. In Proceedings of the ASME Turbo Expo 2015: Turbine Technical Conference and Exposition. Volume 7B: Structures and Dynamics, Montreal, QC, Canada, 15–19 June 2015; American Society of Mechanical Engineers: New York, NY, USA, 2015; p. V07BT32A012. [Google Scholar]
  20. Chupp, R.E.; Ghasripoor, F.; Turnquist, N.A.; Demiroglu, M.; Aksit, M.F. Advanced Seals for Industrial Turbine Applications: Dynamic Seal Development. J. Propuls. Power 2002, 18, 1260–1266. [Google Scholar] [CrossRef]
  21. Chupp, R.E.; Hendricks, R.C.; Lattime, S.B.; Steinetz, B.M.; Aksit, M.F. Turbomachinery Clearance Control; Glenn Research Center: Cleveland, OH, USA, 2007. Available online: https://ntrs.nasa.gov/citations/20070005016 (accessed on 20 August 2024).
  22. FELTMETALTM Abradable Seals—Technetics. Available online: https://technetics.com/resources/video-library/?wchannelid=6dz3bth5yd&wmediaid=g08vko9zm3 (accessed on 1 July 2025).
  23. Dadouche, A.; Conlon, M.J.; Dmochowski, W.; Liko, B.; Bedard, J.-P. Experimental Evaluation of Abradable Seal Performance at High Temperature. In Proceedings of the ASME Turbo Expo 2008: Power for Land, Sea, and Air. Volume 5: Structures and Dynamics, Parts A and B, Berlin, Germany, 9–13 June 2008; ASMEDC: New York, NY, USA, 2008; pp. 143–150. [Google Scholar] [CrossRef]
  24. Scrinzi, E.; Giovannetti, I.; Sheng, N.; Leblanc, L. Development of New Abradable/Abrasive Sealing Systems for Clearance Control in Gas Turbines. In Proceedings of the ASME 2013 Turbine Blade Tip Symposium, Hamburg, Germany, 30 September–3 October 2013; American Society of Mechanical Engineers: New York, NY, USA, 2013; p. V001T05A004. [Google Scholar] [CrossRef]
  25. Behera, A.; Saxena, K.K.; Rajak, D.K.; Sehgal, S. Multi-Scale and Multifunctional Coatings and Interfaces for Tribological Contacts, 1st ed.; CRC Press: Boca Raton, FL, USA, 2025; ISBN 978-1-03-263534-7. [Google Scholar] [CrossRef]
  26. Lima, R.S.; Marple, B.R.; Dadouche, A.; Dmochowski, W.; Liko, B. Nanostructured Abradable Coatings for High Temperature Applications. In Proceedings of the ITSC2006, Seattle, WA, USA, 15–18 May 2006; pp. 775–780. [Google Scholar] [CrossRef]
  27. Madabadi, N. Development of Polymeric Abradable Coatings for Aero Engine Applications. Master’s Thesis, Concordia University, Montreal, QC, Canada, 2024. [Google Scholar]
  28. Sporer, D.; Wilson, S.; Giovannetti, I.; Refke, A.; Giannozzi, M. On The Potential of Metal and Ceramic Based Abradables in Turbine Seal Applications. In Proceedings of the 36th Turbomachinery Symposium, Houston, TX, USA, 11–13 September 2007. [Google Scholar]
  29. Wang, L.; Wang, S.; Chen, G.; Zou, Y.; Yu, S.; Xie, E.; Zhao, Q.; Ye, Z.; Ouyang, J.; Wang, Y.; et al. Ceramic-based abradable sealing coatings for advanced aeroengines: Materials design, structural strategies, and multifunctional performance. Extreme Mater. 2025; in press. [Google Scholar] [CrossRef]
  30. Flitney, R. Seals and Sealing Handbook; Elsevier: Amsterdam, The Netherlands, 2014; pp. 105–288. ISBN 978-0-08-099416-1. [Google Scholar] [CrossRef]
  31. Wilson, S. Abradable Thermal Spray Applications and Technology. In Thermal Spray Technology; ASM Handbook; ASM International: Almere, The Netherlands, 2013; Volume 5A. [Google Scholar] [CrossRef]
  32. Tong, Y.-Q.; Shi, Q.-S.; Liu, M.-J.; Li, G.-R.; Li, C.-J.; Yang, G.-J. Lightweight epoxy-based abradable seal coating with high bonding strength. J. Mater. Sci. Technol. 2021, 69, 129–137. [Google Scholar] [CrossRef]
  33. Tong, Y.-Q.; Li, W.; Shi, Q.-S.; Chen, L.; Yang, G.-J. Self-lubricating epoxy-based composite abradable seal coating eliminating adhesive transfer via hierarchical design. J. Mater. Sci. Technol. 2022, 104, 145–154. [Google Scholar] [CrossRef]
  34. Ghorban, M.; Stoyanov, P.; Lima, R.S. A Comprehensive Review of High-Temperature Ceramic Abradable Coatings Used in Aero and Industrial Gas Turbines. In Proceedings of the ITSC 2025, Vancouver, BC, Canada, 5–8 May 2025; pp. 120–128. [Google Scholar] [CrossRef]
  35. Bertuol, K.; Rivadeneira, F.R.E.; Nair, R.B.; Barnett, B.; Moreau, C.; Stoyanov, P. Influence of hBN on the abradable performance of AlSi-based coatings: Bridging the gap between tribological assessment and abradability testing. Surf. Coat. Technol. 2024, 489, 131060. [Google Scholar] [CrossRef]
  36. Baillieu, A.; Rahimov, E.; Marshall, M. The role of thermal properties in the wear mechanisms of an AlSi-polyester abradable. Wear 2025, 562–563, 205618. [Google Scholar] [CrossRef]
  37. Lye, R.; Pellegrino, A.; Bennett, C.; Rouse, J.; Agyakwa, P.; Zumpano, G. Influence of Temperature, Strain Rate, and Condition on the Mechanical Response of an AlSi-PES Abradable. Exp. Mech. 2025, 65, 1259–1278. [Google Scholar] [CrossRef]
  38. Rajendran, R. Gas turbine coatings—An overview. Eng. Fail. Anal. 2012, 26, 355–369. [Google Scholar] [CrossRef]
  39. Cawley, J.D. Overview of Zirconia with Respect to Gas Turbine Applications. 1 March 1984. Available online: https://ntrs.nasa.gov/citations/19840013672 (accessed on 1 July 2025).
  40. Li, C.; Chai, Y.; Wang, Q.; Wei, S.; Du, F.; Yan, W.; Yan, G.; Liu, W.; Yang, L.; Zhou, Y. Effect of calcium carbonate on the thermal shock behavior of YSZ-based abradable sealing coatings. Ceram. Int. 2025, 51, 8408–8419. [Google Scholar] [CrossRef]
  41. Yang, S.; Gao, S.; Xue, W.; Wu, B.; Zhang, J.; Duan, D. High-Speed Rubbing Behavior Between Nickel-Based Superalloy Blades and Ceramic-Based Abradable Coatings. Tribol. Lett. 2023, 71, 128. [Google Scholar] [CrossRef]
  42. Schmid, R.K.; Ghasripoor, F.; Dorfman, M.; Wei, X. An Overview of Compressor Abradables. In Proceedings of the 1st International Thermal Spray Conference, ITSC 2020, Montreal, QC, Canada, 8–11 May 2000; pp. 1087–1093. [Google Scholar] [CrossRef]
  43. Arendarchuck, B.E.; Bertuol, K.; Rivadeneira, F.; de Castilho, B.C.N.M.; Barnett, B.; Moreau, C.; Stoyanov, P. Tribological evaluation of Cu-based abradable coating. Wear 2025, 570, 206034. [Google Scholar] [CrossRef]
  44. Shamloo, A.; Fathi, B.; Elkoun, S.; Rodrigue, D.; Soldera, A. Impact of compression molding conditions on the thermal and mechanical properties of polyethylene. J. Appl. Polym. Sci. 2018, 135, 46176. [Google Scholar] [CrossRef]
  45. Johnston, R.E.; Evans, W.J. Freestanding abradable coating manufacture and tensile test development. Surf. Coat. Technol. 2007, 202, 725–729. [Google Scholar] [CrossRef]
  46. Bobzin, K.; Lugscheider, E.; Zwick, J.; Ernst, F.; Sporer, D.; Hopkins, N.; Hertter, M.; Matejicek, J. Microstructure and Properties of New Abradable Seal Coatings for Compressor Applications. In Proceedings of the ITSC2006, Seattle, WA, USA, 15–18 May 2006; pp. 1083–1088. [Google Scholar] [CrossRef]
  47. Chauvette, J.; Hia, I.L.; Pierre, J.; Chenier, G.; Farahani, R.D.; Piccirelli, N.; Therriault, D. Non-Planar Multiprocess Additive Manufacturing of Multifunctional Composites. Adv. Mater. Technol. 2023, 8, 2300399. [Google Scholar] [CrossRef]
  48. Guo, X.; Li, C.; Li, L.; Yuan, Z.; Wang, X.; Zhang, W.; Liu, J.; Chen, G.; Cui, X.; Xu, Y. Yttrium-Stabilized Zirconia Ceramics Fabrication through Material Extrusion 3D Printing. J. Mater. Eng. Perform. 2025, 34, 7584–7591. [Google Scholar] [CrossRef]
  49. Zou, C.; Ou, Y.; Zhou, W.; Li, Z.; Zheng, P.; Guo, X. Microstructure and Properties of Hot Pressing Sintered SiC/Y3Al5O12 Composite Ceramics for Dry Gas Seals. Materials 2024, 17, 1182. [Google Scholar] [CrossRef]
  50. Padture, N.P. Advanced structural ceramics in aerospace propulsion. Nat. Mater. 2016, 15, 804–809. [Google Scholar] [CrossRef] [PubMed]
  51. Pawłowski, L. The Science and Engineering of Thermal Spray Coatings, 2nd ed.; Wiley: Chichester, UK; Hoboken, NJ, USA, 2008; ISBN 978-0-471-49049-4. [Google Scholar]
  52. Bertuol, K.; Ribas, M.T.; Mayer, A.R.; Pukasiewicz, A.G.M.; Siqueira, I.B.a.F.; Chicoski, A.; de Souza, M.J. Study of HVOF Parameter Influence on Microstructure and Wear Resistance of Cr3C2-25NiCr Coatings. In Proceedings of the ITSC2019, Yokohama, Japan, 26–29 May 2019; ASM International: Almere, The Netherlands, 2019; pp. 320–325. [Google Scholar] [CrossRef]
  53. Takimi, A.S. Obtenção de Superligas NiCrAIY Nanoestruturadas por Moagem de Alta Energia e Sua Aplicação por Aspersão Térmica Hipersônica (HVOF). Master’s Thesis, Universidade Federal de Santa Catarina, Florianópolis, Brazil.
  54. Sidhu, T.S.; Prakash, S.; Agrawal, R.D. Studies on the properties of high-velocity oxy-fuel thermal spray coatings for higher temperature applications. Mater. Sci. 2005, 41, 805–823. [Google Scholar] [CrossRef]
  55. Brossard, S. Microstructural Analysis of Thermal Spray Coatings by Electron Microscopy. Ph.D. Thesis, UNSW Sydney, Kensington, Australia, 2010. [Google Scholar]
  56. Meghwal, A.; Anupam, A.; Murty, B.S.; Berndt, C.C.; Kottada, R.S.; Ang, A.S.M. Thermal Spray High-Entropy Alloy Coatings: A Review. J. Therm. Spray Technol. 2020, 29, 857–893. [Google Scholar] [CrossRef]
  57. Bertuol, K. Análise da Influência de Parâmetros de Shot Peening na Dureza Superficial, Rugosidade e Tensão Residual em aço ASTM A743-CA6NM—Analysis of the Influence of Shot Peening Parameters on Surface Hardness, Roughness and Residual Stress in Steel ASTM A743-CA6NM. Bachelor’s Thesis, Federal University of Technology—Parana, Ponta Grossa, Brazil, 2014. [Google Scholar]
  58. Mayer, A.R.; Bertuol, K.; Siqueira, I.B.A.F.; Chicoski, A.; Váz, R.F.; de Sousa, M.J.; Pukasiewicz, A.G.M. Evaluation of cavitation/corrosion synergy of the Cr3C2-25NiCr coating deposited by HVOF process. Ultrason. Sonochem. 2020, 69, 105271. [Google Scholar] [CrossRef]
  59. Bertuol, K. Estudo do Efeito Sinérgico Cavitação/Erosão em Revestimentos de Carboneto de Cromo e Tungstênio Depositados por Aspersão Térmica de Alta Velocidade—Study of Synergistic Cavitation/Erosion Effect on Chromium and Tungsten Carbide Coatings Deposited by High Velocity Oxy-Fuel. Master’s Thesis, Universidade Tecnológica Federal do Paraná, Curitiba, Brazil, 2020. [Google Scholar]
  60. Hanson, T.C.; Hackett, C.M.; Settles, G.S. Independent control of HVOF particle velocity and temperature. J. Therm. Spray Technol. 2002, 11, 75–85. [Google Scholar] [CrossRef]
  61. Kumar, S.S.; Prasad, C.D.; Hanumanthappa, H. Role of Thermal Spray Coatings on Erosion, Corrosion, and Oxidation in Various Applications: A Review. J. Bio-Tribo-Corros. 2024, 10, 22. [Google Scholar] [CrossRef]
  62. Ang, A.S.M.; Berndt, C.C. A review of testing methods for thermal spray coatings. Int. Mater. Rev. 2014, 59, 179–223. [Google Scholar] [CrossRef]
  63. Metco, O. Atmospheric Plasma Spray Solutions. Plasma Solut. 2022, 3, 1–20. [Google Scholar]
  64. Bergmann, C.P.; Vicenzi, J. Protection against Erosive Wear Using Thermal Sprayed Cermet: A Review. In Protection Against Erosive Wear Using Thermal Sprayed Cermet; Springer: Berlin/Heidelberg, Germany, 2011; pp. 1–77. ISBN 978-3-642-21986-3. [Google Scholar] [CrossRef]
  65. Lugscheider, E.; Barimani, C.; Eckert, P.; Eritt, U. Modeling of the APS plasma spray process. Comput. Mater. Sci. 1996, 7, 109–114. [Google Scholar] [CrossRef]
  66. Stringer, J.; Marshall, M.B. High speed wear testing of an abradable coating. Wear 2012, 294–295, 257–263. [Google Scholar] [CrossRef]
  67. Xue, W.; Gao, S.; Duan, D.; Zhang, J.; Liu, Y.; Li, S. Effects of blade material characteristics on the high-speed rubbing behavior between Al-hBN abradable seal coatings and blades. Wear 2018, 410–411, 25–33. [Google Scholar] [CrossRef]
  68. Oerlikon Metco, Material Product Data Sheet—CoNiCrAlY-BN/Polyester Abradable Thermal Spray Powders. Available online: https://mymetco.oerlikon.com/en-us/product/metco2043 (accessed on 10 August 2025).
  69. Jech, D.; Čelko, L.; Komarov, P.; Ziegelheim, J.; Česánek, Z.; Schubert, J. The Role of Different Atmospheric Plasma Spray Parameters on Microstructure of Abradable AlSi-Polyester Coatings. Solid State Phenom. 2017, 270, 224–229. [Google Scholar] [CrossRef]
  70. Azmeera, A.K.; Jadhav, P.; Lande, C. Effect of Change in Material Properties of the Abradable Coating on the Wear Behavior of It—Microstructure Model-Based Analysis Approach. Lubricants 2025, 13, 22. [Google Scholar] [CrossRef]
  71. Xu, F.; Tan, Y.; Sun, H.; Wang, B.; Zhou, X.; Sun, J. Corrosion behavior and mechanism of NiCrAl–NiC abradable sealing coating system in NaCl solution. Mater. Chem. Phys. 2024, 316, 129059. [Google Scholar] [CrossRef]
  72. Maozhong, Y.; Baiyun, H.; Jiawen, H. Erosion wear behaviour and model of abradable seal coating. Wear 2002, 252, 9–15. [Google Scholar] [CrossRef]
  73. Alqallaf, J.; Ali, N.; Teixeira, J.A.; Addali, A. Solid Particle Erosion Behaviour and Protective Coatings for Gas Turbine Compressor Blades—A Review. Processes 2020, 8, 984. [Google Scholar] [CrossRef]
  74. Malvi, B.; Roy, M. Elevated temperature erosion of abradable seal coating: Original scientific paper. J. Electrochem. Sci. Eng. 2022, 12, 889–899. [Google Scholar] [CrossRef]
  75. Johnston, R.E. Mechanical characterisation of AlSi-hBN, NiCrAl-Bentonite, and NiCrAl-Bentonite-hBN freestanding abradable coatings. Surf. Coat. Technol. 2011, 205, 3268–3273. [Google Scholar] [CrossRef]
  76. Arendarchuck, B.E.; Bertuol, K.; Rivadeneira, F.; de Castilho, B.C.N.M.; Barnett, B.; Moreau, C.; Stoyanov, P. Unveiling the influence of nickel on the erosion and the tribological performance of AlSi-based abradable coatings. J. Mater. Sci. 2024, 59, 22266–22282. [Google Scholar] [CrossRef]
  77. Chupp, R.E.; Hendricks, R.C.; Lattime, S.B.; Steinetz, B.M. Sealing in Turbomachinery. J. Propuls. Power 2006, 22, 313–349. [Google Scholar] [CrossRef]
  78. Mittal, D.; Singh, D.; Kumar Sharma, S. Thermal Characteristics and Tribological Performances of Solid Lubricants: A Mini Review. In Advances in Rheology of Materials; Dutta, A., Muhamad Ali, H., Eds.; IntechOpen: London, UK, 2023; ISBN 978-1-83769-996-4. [Google Scholar] [CrossRef]
  79. John, M.; Menezes, P.L. Self-Lubricating Materials for Extreme Condition Applications. Materials 2021, 14, 5588. [Google Scholar] [CrossRef]
  80. Sun, X.; Zhang, J.; Pan, W.; Wang, W.; Tang, C. A review on the preparation and application of BN composite coatings. Ceram. Int. 2023, 49, 24–39. [Google Scholar] [CrossRef]
  81. Aussavy, D. Processing Characterization and Modeling of Thermomechanical Properties of Threee Abradable Coatings: NiCrAl-Bentonite, CoNiCrAlY-BN-Polyester, and YSZ-Polyester. Ph.D. Thesis, Université de Technologie de Belfort-Montbeliard, Belfort, France, 2016. [Google Scholar]
  82. Tang, J.; Yu, F.; Zhang, H.; Chen, D. Effect of Microstructure Refining on the Thermal Stability and Wear Resistance of Abradable AlSi-Polyester Coating. J. Therm. Spray Technol. 2021, 30, 1615–1623. [Google Scholar] [CrossRef]
  83. Ma, X.; Matthews, A. Investigation of abradable seal coating performance using scratch testing. Surf. Coat. Technol. 2007, 202, 1214–1220. [Google Scholar] [CrossRef]
  84. Watson, M.; Marshall, M. Wear mechanisms at the blade tip seal interface. Wear 2018, 404–405, 176–193. [Google Scholar] [CrossRef]
  85. Skiba, S.; Faure, L.; Philippon, S.; Papasidero, J. Experimental Investigation of the Mechanical Behavior of an AlSi-PE Abradable Coating at High Strain Rates for a Large Range of Temperatures. J. Dyn. Behav. Mater. 2020, 6, 213–223. [Google Scholar] [CrossRef]
  86. Martinet, B.; Cappella, A.; Philippon, S.; Montebello, C. Effect of temperature on wear mechanisms of an aluminium—Based abradable coating for aircraft engines after a dynamic interaction with a Ti6Al4V blade. Wear 2020, 446–447, 203202. [Google Scholar] [CrossRef]
  87. Liu, T.; Liu, J.; Zhang, D.; Hou, Y. The Influence of Incursion Rate on Abradability of AlSi-hBN Abradable Seal Coating. In Proceedings of the International Thermal Spray Conference, ITSC 2024, Milan, Italy, 29 April–1 May 2024; pp. 159–165. [Google Scholar] [CrossRef]
  88. Yang, S.; Gao, S.; Xue, W.; Wu, B.; Duan, D. Structural design and high temperature tribological behavior of a new turbine blade tip protective coating. Surf. Coat. Technol. 2023, 457, 129316. [Google Scholar] [CrossRef]
  89. Schmid, R.; Nicoll, A.R. Advances in Abradable Coatings for Gas Turbines. In Proceedings of the ASME 1994 International Gas Turbine and Aeroengine Congress and Exposition, The Hague, The Netherlands, 13–16 June 1994; American Society of Mechanical Engineers: New York, NY, USA, 1994; p. V005T12A010. [Google Scholar] [CrossRef]
  90. Bertuol, K.; Arendarchuck, B.; Rivadeneira, F.; Nolte, L.; Lehner, M.; Barnett, B.; Moreau, C.; Stoyanov, P. Assessment of AlSi-based abradable coatings with hBN and MoCr additives for aerospace conditions: A novel high-temperature rig approach. Aerosp. Sci. Technol. 2026, 168, 110737. [Google Scholar] [CrossRef]
  91. Bobzin, K.; Wietheger, W.; Heinemann, H.; Dokhanchi, S.R.; Rom, M.; Visconti, G. Prediction of Particle Properties in Plasma Spraying Based on Machine Learning. J. Therm. Spray Technol. 2021, 30, 1751–1764. [Google Scholar] [CrossRef]
  92. Bertuol, K.; Rivadeneira, F.; Arendarchuck, B.; Nair, R.B.; Barnett, B.; Moreau, C.; Stoyanov, P. Effect of Mo and Cr on abradability and tribological performance of AlSi-based abradable coatings. Wear 2025, 571, 205837. [Google Scholar] [CrossRef]
  93. Metco, O. Thermal Spray Materials Guide. 2015. Available online: https://www.ahtstlab.com/wp-content/uploads/2021/05/ThermalSprayMaterialsGuide.pdf (accessed on 10 June 2025).
  94. Zavareh, M.A.; Doustmohammadi, E.; Sarhan, A.A.D.M.; Karimzadeh, R.; Moozarm Nia, P.; Al/Kulpid Singh, R.S. Comparative study on the corrosion and wear behavior of plasma-sprayed vs. high velocity oxygen fuel-sprayed Al8Si20BN ceramic coatings. Ceram. Int. 2018, 44, 12180–12193. [Google Scholar] [CrossRef]
  95. Faraoun, H.I.; Grosdidier, T.; Seichepine, J.-L.; Goran, D.; Aourag, H.; Coddet, C.; Zwick, J.; Hopkins, N. Improvement of thermally sprayed abradable coating by microstructure control. Surf. Coat. Technol. 2006, 201, 2303–2312. [Google Scholar] [CrossRef]
  96. Liu, Y.D.; Zhang, J.P.; Pei, Z.L.; Liu, J.H.; Li, W.H.; Gong, J.; Sun, C. Investigation on high-speed rubbing behavior between abrasive coatings and Al/hBN abradable seal coatings. Wear 2020, 456–457, 203389. [Google Scholar] [CrossRef]
  97. Rajaram, G.; Kumaran, S.; Rao, T.S. Sliding Wear Behavior of Al-Si/Graphite Composite. Tribol. Trans. 2010, 54, 115–121. [Google Scholar] [CrossRef]
  98. Ma, X.; Matthews, A. Evaluation of abradable seal coating mechanical properties. Wear 2009, 267, 1501–1510. [Google Scholar] [CrossRef]
  99. Guilemany, J.M.; Navarro, J.; Lorenzana, C.; Vizcaino, S.; Miguel, J.M. Tribological Behaviour of Abradable Coatings Obtained by Atmospheric Plasma Spraying (APS). In Proceedings of the International Thermal Spray Conference 2001, Singapore, 28–30 May 2001; pp. 1115–1118. [Google Scholar] [CrossRef]
  100. Zhang, N.; Shen, J.; Xuan, H.; Hu, Y.; Hong, W. Evaluation of an AlSi-polyester abradable seal coating performance using high-temperature and high-velocity abrasion tests. Proc. Inst. Mech. Eng. Part J J. Eng. Tribol. 2016, 230, 842–851. [Google Scholar] [CrossRef]
  101. Mutasim, Z.; Hsu, L.; Wong, E. Evaluation of plasma sprayed abradable coatings. Surf. Coat. Technol. 1992, 54–55, 39–44. [Google Scholar]
  102. Cuny, M.; Philippon, S.; Chevrier, P.; Garcin, F. Experimental Measurement of Dynamic Forces Generated during Short-Duration Contacts: Application to Blade-Casing Interactions in Aircraft Engines. Exp. Mech. 2014, 54, 101–114. [Google Scholar] [CrossRef]
  103. Boddenberg, K.; Kock, B.; Dorfman, M.; Russo, L.; Nestler, M. A New Aluminium Silicon-Boron Nitride Abradable for Compressor Components. In Proceedings of the ITSC 1998, Nice, France, 25–29 May 1998; pp. 1049–1054. [Google Scholar] [CrossRef]
  104. Jońca, J.; Malard, B.; Soulié, J.; Sanviemvongsak, T.; Selezneff, S.; Vande Put, A. Oxidation behaviour of a CoNiCrAlY/h-BN based abradable coating. Corros. Sci. 2019, 153, 170–177. [Google Scholar]
  105. Chappel, D.; Howe, H.; Vo, L. Abradable seal testing—Blade temperatures during low speed rub event. In Proceedings of the 37th Joint Propulsion Conference and Exhibit, Salt Lake City, UT, USA, 8–11 July 2001; American Institute of Aeronautics and Astronautics: Reston, VA, USA, 2001. [Google Scholar]
  106. Tan, W.; Zois, D.; Wilson, S.; Dorfman, M.R. Investigation of High Temperature Compressor Abradable Coatings for Gas Turbine Applications. In Proceedings of the ITSC2018, Orlando, FL, USA, 1–4 December 2001; pp. 355–360. [Google Scholar] [CrossRef]
  107. Ju, C.; Li, Q.; Wang, Z.L.; Song, Q.H.; Li, J.J.; Sun, Z.P.; Zhang, Y.F. Reaction mechanism comparison of AlSi-polyester and aluminum bronze/polyester plasma spraying. Dig. J. Nanomater. Biostructures 2021, 16, 1411–1425. [Google Scholar] [CrossRef]
  108. Yang, S.-Y.; Guo, D.; Cheng, X.-W.; Liu, J.-M.; Yu, Y.-G. Corrosion behaviour of NiCrFeAl-hBN seal coatings in oxidation environments at a high temperature. Rare Met. 2021, 40, 212–218. [Google Scholar] [CrossRef]
  109. Nava, Y.; Mutasim, Z.; Coe, M. Abradable Coatings for Low-Temperature Applications. In Proceedings of the ITSC2001, Singapore, 28–30 May 2001; pp. 263–268. [Google Scholar] [CrossRef]
  110. Johnston, R.E. The Sensitivity of Abradable Coating Residual Stresses to Varying Material Properties. J. Therm. Spray Technol. 2009, 18, 1004–1013. [Google Scholar] [CrossRef]
  111. Cappella, A.; Philippon, S.; Pinheiro, L. Micro-Ct and Ai-Based Analysis of Induced Changes in Porosity of Alsi-Pe Abradable Coatings Due to Short-Term Loading and High Temperature. Surf. Coat. Technol. 2025, 514, 132518. [Google Scholar] [CrossRef]
  112. Xiao, J.; Chen, Y.; Chen, D.; Tian, J.; Ouyang, H.; Wang, A. Interactions between blades and abradable coatings: A numerical approach considering geometrical nonlinearity. Int. J. Mech. Sci. 2021, 191, 106052. [Google Scholar] [CrossRef]
  113. Al-Bender, F. Fundamentals of Friction Modeling; ASPE—The American Society of precision Engineering: Raleigh, NC, USA, 2010; Volume 48, ISBN 978-1-887706-53-7. [Google Scholar]
  114. Cheng, J.; Hu, X.; Lancaster, D.; Sun, X.; Joost, W. Modeling deformation and failure in AlSi-polyester abradable sealcoating material using microstructure-based finite element simulation. Mater. Des. 2022, 219, 110791. [Google Scholar] [CrossRef]
  115. Padova, C.; Barton, J.; Dunn, M.J.; Manwaring, S.; Young, G.; Adams, M., Jr.; Adams, M. Development of an Experimental Capability to Produce Controlled Blade Tip/Shroud Rubs at Engine Speed; ASME American Society of Mechanical Engineers: New York, NY, USA, 2005. [Google Scholar]
  116. Zhang, B.; Marshall, M.; Lewis, R. Investigating Al-Si base abradable material removal mechanism with axial movement in labyrinth seal system. Wear 2022, 510–511, 204496. [Google Scholar] [CrossRef]
  117. Chupp, R.E.; Lau, Y.-C.; Ghasripoor, F.; Baldwin, D.J.; Ng, C.; McGovern, T.; Berkeley, D. Development of Higher Temperature Abradable Seals for Gas Turbine Applications. In Proceedings of the ASME Turbo Expo 2004: Power for Land, Sea, and Air, Vienna, Austria, 14–17 June 2004; ASMEDC: New York, NY, USA, 2004; pp. 221–229. [Google Scholar] [CrossRef]
  118. Bertuol, K.; Rivadeneira, F.; Nair, R.; Stoyanov, P. Advancing Abradable Evaluation: A Comprehensive Review and Development of an Innovative Cost-Effective Methodology. In Proceedings of the 27th International Congress of Mechanical Engineering, Florianópolis, Brazil, 4–8 December 2023. [Google Scholar] [CrossRef]
  119. Mandard, R.; Witz, J.-F.; Boidin, X.; Fabis, J.; Desplanques, Y.; Meriaux, J. Interacting force estimation during blade/seal rubs. Tribol. Int. 2015, 82, 504–513. [Google Scholar] [CrossRef]
Coatings 15 01216 g001
Figure 1. Schematic representation of blade–abradable interaction in a gas turbine engine. Adapted from [22].
Figure 1. Schematic representation of blade–abradable interaction in a gas turbine engine. Adapted from [22].
Coatings 15 01216 g001
Coatings 15 01216 g002
Figure 2. Schematic representation of a generic thermal spray process.
Figure 2. Schematic representation of a generic thermal spray process.
Coatings 15 01216 g002
Coatings 15 01216 g003
Figure 3. Thermal spray map illustrating the (a) classification of the process by energy source [31,56,61] and (b) typical operational ranges of the major techniques based on particle velocity, temperature, and size, adapted from [62].
Figure 3. Thermal spray map illustrating the (a) classification of the process by energy source [31,56,61] and (b) typical operational ranges of the major techniques based on particle velocity, temperature, and size, adapted from [62].
Coatings 15 01216 g003
Coatings 15 01216 g004
Figure 4. Schematic model of the atmospheric plasma spray process.
Figure 4. Schematic model of the atmospheric plasma spray process.
Coatings 15 01216 g004
Coatings 15 01216 g005
Figure 5. Schematic highlighting the main demanding properties of abradable materials and the contrast between erosion resistance and abradability.
Figure 5. Schematic highlighting the main demanding properties of abradable materials and the contrast between erosion resistance and abradability.
Coatings 15 01216 g005
Coatings 15 01216 g006
Figure 6. Metallic-based abradable coating with polymer filler via macro photography, micro-CT, and SEM imaging.
Figure 6. Metallic-based abradable coating with polymer filler via macro photography, micro-CT, and SEM imaging.
Coatings 15 01216 g006
Coatings 15 01216 g007
Figure 7. Cross-section images of Al-based coatings with varying filler material content and HR15Y hardness values. Adapted from [84].
Figure 7. Cross-section images of Al-based coatings with varying filler material content and HR15Y hardness values. Adapted from [84].
Coatings 15 01216 g007
Coatings 15 01216 g008
Figure 8. (a) Schematic of jet engine areas and their range of operational temperatures. (b) Temperature regime map illustrating the suitability of different abradable coatings by engine area. Adapted from [1].
Figure 8. (a) Schematic of jet engine areas and their range of operational temperatures. (b) Temperature regime map illustrating the suitability of different abradable coatings by engine area. Adapted from [1].
Coatings 15 01216 g008
Coatings 15 01216 g009
Figure 9. Simplified schematic of abradability testing.
Figure 9. Simplified schematic of abradability testing.
Coatings 15 01216 g009
Coatings 15 01216 g010
Figure 10. (a) Schematic of the abradable test rig developed by Sulzer Metco; (b) Abradable specimens illustrating different types of abradability. Adapted from [14].
Figure 10. (a) Schematic of the abradable test rig developed by Sulzer Metco; (b) Abradable specimens illustrating different types of abradability. Adapted from [14].
Coatings 15 01216 g010
Table 1. Classification of abradable coating materials based on their primary chemical composition [10,26,27,28,29].
Table 1. Classification of abradable coating materials based on their primary chemical composition [10,26,27,28,29].
Polymeric [10,25,27,30]Ceramic [26,28,29]Metallic [10,28,31]
Widely investigated materials
Epoxy-based [27,32,33]ZrO2- 7Y2O3 [26,29,34]AlSi + 40Polyester [35,36,37]
Alternative materials
Polytetrafluoroethylene (PTFE)DySZ-basedCo-based alloys
Polyetheretherketone (PEEK)YAG-basedNi-based alloys
Polyamideimide (PAI)Yb-basedCu-based alloys
Table 2. Characteristics of common manufacturing methods used for abradable seal coatings.
Table 2. Characteristics of common manufacturing methods used for abradable seal coatings.
Manufacturing MethodCharacteristicsTypical Materials
Compression moldingHigher processing pressures during polymer melt forming may enhance mechanical properties and increase crystallinity, leading to denser, harder-to-cut, and stronger materials [27,44].Polymers and
composites
SinteringAids to grain growth at elevated temperatures, improving bonding strength while redistributing internal defects, yet retaining controlled porosity [26,29].Ceramics and
composites
Thermal sprayExhibit strong anisotropy, as splats solidify in layered sequences where particle shape and inter-splat bonding largely govern the resulting properties [31,45].Metals and
composites
Table 3. Conventional metallic abradable coatings. Adapted from [93].
Table 3. Conventional metallic abradable coatings. Adapted from [93].
Abradable Materials
(Metallic-Based)		Operating Temperature [93]Description [93]References
Aluminum-based AlloyAlSi + BN<450 °CGood erosion resistance[4,16,67,75,94,95,96]
AlSi + Graphite<480 °CBalance of abradability and erosion resistance[83,97,98,99]
AlSi + Polymer<325 °CBalance of abradability and erosion resistance[15,16,69,100,101,102]
AlSi + Polyester + BN<325 °CBalance of abradability and erosion resistance[103]
Cobalt-based AlloyCoNiCrAlY + BN + Polyester<750 °CGreat corrosion resistance[11,26,71,74,104,105,106]
Copper-based AlloyCuAl (Al+ Bronze) + Polyester<650 °CGood corrosion resistance[80,101,107]
Nickel-based AlloyNi + Graphite<480 °CBalance of lubricity and erosion resistance[83,98,99,105,106]
NiCrAl + Bentonite<650 °CGood erosion resistance[75,81,95,106]
NiCrFeAl + BN<815 °CBalance of lubricity and erosion resistance[106,108,109]
Table 4. Typical main inputs and outputs of abradability tests and their corresponding units.
Table 4. Typical main inputs and outputs of abradability tests and their corresponding units.
CategoryTypeKey ParametersUnitsMain Measurement Methods
QuantitativeInputBlade speed[rpm or m/s]Tachometer/encoder/high-speed camera
Incursion rate[μm/s or μm/pass]Linear displacement/laser sensor/high-speed camera
Incursion depth[μm]Laser sensor/profilometry/gauges
Operating temperature[°C]Thermocouples/IR pyrometer
OutputBlade Wear[µm, % loss]Optical surface analysis/profilometry/scale/stroboscopic image
Coating Wear[µm, mm3/Nm]Optical surface analysis/profilometry/scale
Rub Grooves profile[μm]Profilometry/roughness tester
Reaction Forces [kN]Load cell/strain gauges/force transducer
Rubbing Temperature[°C]Thermocouples/IR pyrometer/IR camera
QualitativeInputAbradable material-EDS/X-ray/RAMAN
Blade material-EDS/X-ray/RAMAN
OutputAdhesive Transfer-SEM/optical surface analysis
Wear Mechanism-SEM/optical surface analysis
Densification-SEM/optical surface analysis
Debris Characteristics-Laser-diffractometer/SEM/EDS
Rub Grooves Characteristics-SEM/optical surface analysis
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Bertuol, K.; Arendarchuck, B.E.; Stoyanov, P. An Overview of Metallic Abradable Coatings in Gas Turbine Engines. Coatings 2025, 15, 1216. https://doi.org/10.3390/coatings15101216

AMA Style

Bertuol K, Arendarchuck BE, Stoyanov P. An Overview of Metallic Abradable Coatings in Gas Turbine Engines. Coatings. 2025; 15(10):1216. https://doi.org/10.3390/coatings15101216

Chicago/Turabian Style

Bertuol, Kaue, Bruno Edu Arendarchuck, and Pantcho Stoyanov. 2025. "An Overview of Metallic Abradable Coatings in Gas Turbine Engines" Coatings 15, no. 10: 1216. https://doi.org/10.3390/coatings15101216

APA Style

Bertuol, K., Arendarchuck, B. E., & Stoyanov, P. (2025). An Overview of Metallic Abradable Coatings in Gas Turbine Engines. Coatings, 15(10), 1216. https://doi.org/10.3390/coatings15101216

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop