Journal of Composites Science

Research

20 pages, 7135 KiB

Open AccessArticle

Effects of Nanofiber Interleaving on the Strength and Failure Behavior of Co-Cured Composite Joints with Fiber Orientation Mismatch

by Abdul Bari Abdul Raheman, Kaan Bilge and Melih Papila

J. Compos. Sci. 2025, 9(6), 285; https://doi.org/10.3390/jcs9060285 - 2 Jun 2025

Viewed by 283

Abstract

This study investigates the effect of nanofiber interleaving on the mechanical performance of co-cured composite lap joints with effective fiber orientation mismatch at the joint interface. Joint configurations were defined by dominant yarn orientations at the bond line—denoted as (lower-substrate|upper-substrate)—and tested in (0|0), [...] Read more.

This study investigates the effect of nanofiber interleaving on the mechanical performance of co-cured composite lap joints with effective fiber orientation mismatch at the joint interface. Joint configurations were defined by dominant yarn orientations at the bond line—denoted as (lower-substrate|upper-substrate)—and tested in (0|0), (90|90), and mismatched (0|90) setups using an 8-harness satin (8HS) fabric architecture, with and without nanofiber interlayers. Mechanical testing revealed an over ~25% reduction in lap shear strength for the (0|90) configuration relative to the matched (0|0) and (90|90) joints. Nanofiber interleaving effectively restored this loss, achieving strength levels comparable to the matched cases. Statistical analysis using two-way ANOVA and ANOM confirmed that both fiber orientation and nanofiber interleaving significantly influence joint strength, with a notable interaction effect (p < 0.001). Fractographic analysis further showed that nanofibers enhanced delamination resistance by stabilizing crack paths and suppressing crack jumps at crimping sites, especially in (0|90) joints where 0/90 yarn intersections are prone to early failure. These findings underscore the role of nanofiber interleaving in mitigating mismatch-induced failure mechanisms and improving the structural integrity of composite bonded interfaces. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

18 pages, 5335 KiB

Open AccessArticle

Surface Modification of Wood Fibers with Citric Acid as a Sustainable Approach to Developing Novel Polycaprolactone-Based Composites for Packaging Applications

by Laura Simonini and Andrea Dorigato

J. Compos. Sci. 2025, 9(6), 274; https://doi.org/10.3390/jcs9060274 - 29 May 2025

Viewed by 240

Abstract

In this study, novel biodegradable polycaprolactone (PCL)-based composites for sustainable packaging applications were developed by adding surface-treated wood fibers (WFs). Specifically, the WFs were treated with citric acid (CA) to improve the fiber/matrix adhesion and then melt compounded with a PCL matrix. The [...] Read more.

In this study, novel biodegradable polycaprolactone (PCL)-based composites for sustainable packaging applications were developed by adding surface-treated wood fibers (WFs). Specifically, the WFs were treated with citric acid (CA) to improve the fiber/matrix adhesion and then melt compounded with a PCL matrix. The presence of an absorption peak at 1720 cm⁻¹ in the Fourier transform infrared (FTIR) spectra of CA-treated WFs, coupled with the increase in the storage modulus and complex viscosity in the rheological analysis, confirmed the occurrence of an esterification reaction between CA and WFs, with a consequent increase in interfacial interactions with the PCL matrix. Scanning electron microscopy (SEM) of the cryo-fractured surface of the composites highlighted that PCL was able to efficiently wet the fibers after the CA treatment, with limited fiber pull-out. Quasi-static tensile tests showed that the composites reinforced with CA-treated wood fibers exhibited a significant increase in yield strength (about 30% with a WF amount of 10% at 0 °C) and also a slight improvement in the VICAT softening temperature (about 6 °C with respect to neat PCL). Water absorption tests showed reduced water uptake in CA-treated composites, consistent with the reduced hydrophilicity confirmed by higher water contact angle values. Therefore, the results obtained in this work highlighted the potential of CA-treated WFs as reinforcement for PCL composites, contributing to the development of eco-sustainable and high-performance packaging materials. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

10 pages, 7299 KiB

Open AccessArticle

Molding Process Effects on the Internal Structures of High-Performance Discontinuous Carbon Fiber Reinforced Thermoplastics

by Yi Wan and Jun Takahashi

J. Compos. Sci. 2025, 9(6), 270; https://doi.org/10.3390/jcs9060270 - 29 May 2025

Viewed by 227

Abstract

High-performance discontinuous carbon-fiber-reinforced thermoplastics (CFRTPs) offer promising manufacturing flexibility and recyclability for advanced composite applications. However, their mechanical performance and reliability strongly depend on the internal fiber architecture, which is largely determined by the molding process. In this study, three distinct compression molding [...] Read more.

High-performance discontinuous carbon-fiber-reinforced thermoplastics (CFRTPs) offer promising manufacturing flexibility and recyclability for advanced composite applications. However, their mechanical performance and reliability strongly depend on the internal fiber architecture, which is largely determined by the molding process. In this study, three distinct compression molding approaches—CFRTP sheet molding compounds (SMCs), bulk molding compounds (BMCs), and free-edge molding compounds (FMCs)—were systematically evaluated to investigate how processing parameters affect fiber orientation, tape deformation, and impregnation quality. X-ray micro-computed tomography (XCT) was employed to visualize and quantify the internal structures of each material, focusing on the visualization and quantification of in-plane and out-of-plane fiber alignment and other internal structure features. The results indicate that CFRTP-SMC retains largely intact tape layers and achieves better impregnation, leading to more uniform and predictable internal geometry. Although CFRTP-BMC exhibits greater tape deformation and splitting due to increased flow, its simpler molding process and better tolerance for tape shape distortion suggest potential advantages for recycled applications. In contrast, CFRTP-FMC shows significant tape fragmentation and poor impregnation, particularly near free edges. These findings underscore the critical role of a controlled molding process in achieving a consistent internal structure for these materials for the first time. This study highlights the utility of advanced XCT methods for optimizing process design and advancing the use of high-performance discontinuous CFRTP in industry. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

16 pages, 3482 KiB

Open AccessArticle

Conducting EVA/GNP Composite Films with Multifunctional Applications: Effect of the Phosphonium-Based Ionic Liquid

by André A. Schettini, Debora P. Schmitz, Beatriz S. Cunha and Bluma G. Soares

J. Compos. Sci. 2025, 9(6), 256; https://doi.org/10.3390/jcs9060256 - 23 May 2025

Viewed by 323

Abstract

The application of graphene nanoplatelets (GNPs) in polymer composites is a challenge due to their high tendency to agglomerate and restack during processing. In this work, alkyl phosphonium-based ionic liquid was used to assist the dispersion of GNP in an ethylene-vinyl acetate (EVA) [...] Read more.

The application of graphene nanoplatelets (GNPs) in polymer composites is a challenge due to their high tendency to agglomerate and restack during processing. In this work, alkyl phosphonium-based ionic liquid was used to assist the dispersion of GNP in an ethylene-vinyl acetate (EVA) matrix, through a melt-mixing procedure. The mechanical properties and creep resistance of the films prepared by the film extrusion process were evaluated. The results demonstrated that the noncovalent treatment of GNP with the ionic liquid (IL) enhanced the electrical conductivity and creep stability of the EVA composites. The microwave absorbing properties were studied in the X-band and Ku-band. A reflection loss (RL) of −15 dB for EVA containing 0.5 wt% of GNP and 1:1 wt% of GNP/IL was achieved. The use of a multi-layered structure containing thin film layers was efficient for enhancing the microwave absorbing performance, with a minimum RL of −24.6 dB and effective absorption bandwidth of 4.3 GHz. This result is attributed to the internal reflection and scattering of the radiation between layers. The use of simple, low-cost materials and procedures, combined with the system’s excellent mechanical and electrical properties, makes it a promising candidate for multifunctional applications as electrostatic dissipative and microwave absorbing materials for electronic packaging and other electronic devices. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

12 pages, 4072 KiB

Open AccessArticle

Experimental Study of Paraffin-Based Composites Incorporating Different Iron–Carbon Core–Shell Particles: Analysis of Gamma-Ray Shielding and Thermal Properties

by Jolanta Sobczak, Marco A. Marcos, Javier P. Vallejo, Luis Lugo and Gaweł Żyła

J. Compos. Sci. 2025, 9(5), 243; https://doi.org/10.3390/jcs9050243 - 15 May 2025

Viewed by 530

Abstract

Shielding nanocomposites against gamma-rays are increasingly recognized as an advantageous alternative over conventional lead-based covers. In particular, constantly evolving nanocomposites are geared toward improving features such as flexibility and low toxicity. Taking this into consideration, this study introduces composites that offer versatile options [...] Read more.

Shielding nanocomposites against gamma-rays are increasingly recognized as an advantageous alternative over conventional lead-based covers. In particular, constantly evolving nanocomposites are geared toward improving features such as flexibility and low toxicity. Taking this into consideration, this study introduces composites that offer versatile options in shape definition outside laboratory conditions. The proposed covers contain paraffin as the main compound, where the fillers are iron nanopowders with hydrophobic and hydrophilic carbon shells, at 10 wt.%. The composite preparation process relies on safe, commercially purchased compounds and utilizes user-friendly equipment. This experimental study includes the determination of the shielding properties of the manufactured composites against gamma radiation from ⁶⁰Co along with their thermal properties, specifically the heat capacity. The achieved results show that incorporating core–shell particles improves the shielding properties, with half-value layers of ca. 15 cm and ca. 14 cm for the pure matrix and composites, respectively. Regarding the differential scanning calorimetry measurements, this study reveals that the composites possess relatively low phase transition temperature values. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

21 pages, 8395 KiB

Open AccessArticle

Deep Artificial Neural Network Modeling of the Ablation Performance of Ceramic Matrix Composites in the Hydrogen Torch Test

by Jayanta Bhusan Deb, Christopher Varela, Fahim Faysal, Yiting Wang, Chiranjit Maiti and Jihua Gou

J. Compos. Sci. 2025, 9(5), 239; https://doi.org/10.3390/jcs9050239 - 13 May 2025

Viewed by 416

Abstract

In recent years, there has been increasing interest in new materials such as ceramic matrix composites (CMCs) for power generation and aerospace propulsion applications through hydrogen combustion. This study employed a deep artificial neural network (DANN) model to predict the ablation performance of [...] Read more.

In recent years, there has been increasing interest in new materials such as ceramic matrix composites (CMCs) for power generation and aerospace propulsion applications through hydrogen combustion. This study employed a deep artificial neural network (DANN) model to predict the ablation performance of CMCs in the hydrogen torch test (HTT). The study was conducted in three phases to increase the accuracy of the model’s predictions. Initially, to predict the thermal behavior of ceramic composites, two linear machine learning models were used known as Lasso and Ridge regression. In the second step, four decision tree-based ensemble machine learning models, namely random forest, gradient boosting regression, extreme gradient boosting regression, and extra tree regression, were used to improve the prediction accuracy metrics, including root mean square error (RMSE), mean absolute error (MAE), correlation coefficient (R² score), and mean absolute percentage error (MAPE), relative to the previously introduced linear models. Finally, to forecast the thermal stability of CMCs with time, an optimized DANN model with two hidden layers having rectified linear unit activation function was developed. The data collection procedure involved preparing CMCs with continuous Yttria-Stabilized Zirconia (YSZ) fibers and silicon carbide (SiC) matrix using a polymer infiltration and pyrolysis (PIP) technique. The samples were exposed to a hydrogen flame at a high heat flux of 183 W/cm² for a duration of 10 min. A good agreement between the DANN model’s predictions and experimental data with an R² score of 0.9671, RMSE of 16.45, an MAE of 14.07, and an MAPE of 3.92% confirmed the acceptability of the developed neural network model in this study. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Graphical abstract

13 pages, 1787 KiB

Open AccessArticle

Evaluation of Ozonized Gel Application for Stain Removal on Dental Composite Resins

by Paolo Zampetti, Marco Colombo, Maurizio Pascadopoli, Simone Gallo, Claudio Poggio, Jamil Tayybia and Andrea Scribante

J. Compos. Sci. 2025, 9(5), 238; https://doi.org/10.3390/jcs9050238 - 12 May 2025

Viewed by 257

Abstract

Staining removal is an issue of interest in dentistry. Current treatments deal with staining removal on enamel, while few studies concentrate on resin composites. The aim of the current study is to evaluate the efficacy in staining removal of an ozonated gel on [...] Read more.

Staining removal is an issue of interest in dentistry. Current treatments deal with staining removal on enamel, while few studies concentrate on resin composites. The aim of the current study is to evaluate the efficacy in staining removal of an ozonated gel on dental composites. The study sample consisted of 40 specimens of restorative composites: 20 specimens were stained for 1 day in tea solution (tea group) and 20 specimens were stained for 1 day in physiological solution (NaCl group). Both the tea and NaCl groups underwent the experimental treatment as follows: five specimens underwent ozonized gel application, five specimens underwent an ozonized spray, five specimens underwent an application of olive oil, and five specimens were not treated. A colorimetric evaluation was performed with a spectrophotometer, using CIEDE2000 data elaboration at the baseline (T0), after staining (T1), and after staining removal (T2). In the T0–T1 time frame, significantly different color changes (ΔE₀₀) were found between tea groups and NaCl groups (p < 0.05), except for control groups (p > 0.05). After staining removal in the T1–T2 period, no significant differences in ΔE₀₀ were found (p > 0.05). Higher values were found for groups treated with ozonized gel, denoting a stain removal effect. The groups treated with olive oil, instead, exhibited higher ΔE₀₀ values, showing a greater staining effect. In conclusion, the ozonized gel tested showed staining removal activity on restorative resin composites. Future clinical applications are required to validate the in vitro results obtained. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

24 pages, 1148 KiB

Open AccessArticle

Three-Dimensional Magneto-Elastic Analysis of Functionally Graded Plates and Shells

by Salvatore Brischetto and Domenico Cesare

J. Compos. Sci. 2025, 9(5), 214; https://doi.org/10.3390/jcs9050214 - 28 Apr 2025

Viewed by 288

Abstract

This work shows a three-dimensional (3D) layerwise model for static and free vibration analyses of functionally graded piezomagnetic materials (FGPM) spherical shell structures where magnetic and elastic fields are completely coupled. The 3D magneto-elastic governing equations for spherical shells are made of the [...] Read more.

This work shows a three-dimensional (3D) layerwise model for static and free vibration analyses of functionally graded piezomagnetic materials (FGPM) spherical shell structures where magnetic and elastic fields are completely coupled. The 3D magneto-elastic governing equations for spherical shells are made of the three equations of equilibrium in three-dimensional form and the three-dimensional divergence equation for the magnetic induction. Governing equations are written in the orthogonal mixed curvilinear reference system (

α

,

β

, z) allowing the analysis of several curved and flat geometries (plates, cylindrical shells and spherical shells) thanks to proper considerations of the radii of curvature. The static cases, actuator and sensor configurations and free vibration investigations are proposed. The resolution method uses the imposition of the Navier’s harmonic forms in the two in-plane directions and the exponential matrix methodology in the transverse normal direction. Single-layered and multilayered simply-supported FGPM structures have been investigated. In order to understand the behavior of FGPM structures, numerical values and trends along the thickness direction for displacements, stresses, magnetic potential, magnetic induction and free vibration modes are proposed. In the results section, a first assessment phase is proposed to demonstrate the validity of the formulation and to fix proper values for the convergence of results. Therefore, a new benchmark section is presented. Different cases are proposed for several material configurations, load boundary conditions and geometries. The possible effects involved in this problem (magneto-elastic coupling and effects related to embedded materials and thickness values of the layers) are discussed in depth for each thickness ratio. The innovative feature proposed in the present paper is the exact 3D study of magneto-elastic coupling effects in FGPM plates and shells for static and free vibration analyses by means of a unique and general formulation. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

18 pages, 9576 KiB

Open AccessArticle

Cold Forming Hybrid Aluminium–Carbon Fibre-Reinforced Polymer Sheets Joined by Mechanical Interlocking

by Núria Latorre, Daniel Casellas, Josep Costa, Eduard Garcia-Llamas and Jaume Pujante

J. Compos. Sci. 2025, 9(5), 204; https://doi.org/10.3390/jcs9050204 - 24 Apr 2025

Viewed by 552

Abstract

Forming hybrid structures into complex shapes is key to address lightweighting of automotive parts. Recently, an innovative joining technique between aluminium and Carbon Fibre-Reinforced Polymer (CFRP) based on mechanical interlocking through sheet punching has been developed. However, scaling up the solution requires the [...] Read more.

Forming hybrid structures into complex shapes is key to address lightweighting of automotive parts. Recently, an innovative joining technique between aluminium and Carbon Fibre-Reinforced Polymer (CFRP) based on mechanical interlocking through sheet punching has been developed. However, scaling up the solution requires the assessment of challenges, such as multi-material forming and joint integrity, after forming operations. Therefore, this work proves the feasibility of forming aluminium–CFRP prepreg panels into complex omega-shaped profiles following a conventional cold-stamping process. Forming without defects was possible even in specimens featuring mechanical joints generated through punching. The effect of the CFRP position (in the inner or the outer side of the formed profile), the number of mechanical joints, the addition of a Glass Fibre-Reinforced Polymer (GFRP) intermediate layer to prevent galvanic corrosion and adequate lubrication on necking, cracking, springback behaviour and the final geometry after curing were studied. Compression tests were performed to assess the mechanical response of the hybrid profile, and the results showed that the addition of CFRP in the aluminium omega profile changed the buckling behaviour from global bending to axial folding, increasing the maximum compression load. Additionally, the presence of mechanical interlocking joints further improved the mechanical performance and led to a more controlled failure due to buckling localization in the geometric discontinuity. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

14 pages, 1706 KiB

Open AccessArticle

Thermal Stabilization Activities of Metal Oxide γ-Irradiated Styrene–Isoprene–Styrene Nanocomposites

by Traian Zaharescu, Ademar B. Lugāo, Violeta Mangalagiu and Radu Mirea

J. Compos. Sci. 2025, 9(4), 192; https://doi.org/10.3390/jcs9040192 - 17 Apr 2025

Viewed by 556

Abstract

This study provides insights into the stabilization effects of certain oxides (CeO₂, Cr₂O₃, Cd₂O₃, In₂O₃, MnO₂, MgO, Nd₂O₃, and Pr₂O₃ [...] Read more.

This study provides insights into the stabilization effects of certain oxides (CeO₂, Cr₂O₃, Cd₂O₃, In₂O₃, MnO₂, MgO, Nd₂O₃, and Pr₂O₃) in styrene–isoprene–styrene triblock copolymers with respect to neat materials. This study was performed via chemiluminescence (CL), which allowed for the determination of the main parameters characterizing the interphase coexistence: the oxidation induction times, oxidation rates, and onset oxidation temperatures. The improvement in the thermal performances of the pristine and γ-ray-processed samples at a moderate dose was highlighted differently due to the electronic interactions on the particle surface. While the non-isothermal CL measurements pointed to a weaker evolution of oxidation in the studied composites at a higher temperature range over 160 °C, the isothermal CL determinations revealed a delayed start of oxidation, slower oxidation rates, and greater activation energies in the nanocomposite aging patterns. The different individual behaviors of the investigated formulations were ascribed to the dissimilar electronic interactions between the particles and the surrounding matrix, where the oxidation initiators were formed by the molecular fragmentation of the polymer macromolecules. The kinetic features illustrate the influence of the peculiarities due to the electronic interactions. The higher resistance shown by the irradiated samples compared with the non-processed compositions demonstrates the stabilization efficiency of the fillers studied. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Graphical abstract

17 pages, 14026 KiB

Open AccessArticle

Analysis of the Deformation Mechanisms of Fabrics Based on rCF Staple Fiber Yarns for Thermoset Composite Applications

by Tobias Georg Lang, Mir Mohammad Badrul Hasan, Anwar Abdkader, Chokri Cherif and Thomas Gereke

J. Compos. Sci. 2025, 9(4), 173; https://doi.org/10.3390/jcs9040173 - 2 Apr 2025

Viewed by 477

Abstract

The draping of textile semi-finished products for complex geometries is still prone to errors, e.g., wrinkles, gaps, and fiber undulations, leading to reduced mechanical properties of the composite. Reinforcing textiles made from carbon fiber (CF) rovings (i.e., endless continuous fibers) can be draped [...] Read more.

The draping of textile semi-finished products for complex geometries is still prone to errors, e.g., wrinkles, gaps, and fiber undulations, leading to reduced mechanical properties of the composite. Reinforcing textiles made from carbon fiber (CF) rovings (i.e., endless continuous fibers) can be draped mainly based on their ability to deform under in-plane shearing. However, CF rovings are hardly stretchable in the fiber direction. These limited degrees of freedom make the production of complex shell-shaped geometries from standard CF-roving fabrics challenging. Contrary to continuous rovings, this paper investigates the processing of spun yarns made of recycled carbon fibers (rCFs), which are discontinuous staple fibers with defined lengths. rCFs are obtained from end-of-life composites or production waste, making them a sustainable alternative to virgin carbon fibers in the high-performance components of, e.g., automobiles, boats, or sporting goods. These staple fiber-spun yarns are considerably more stretchable, which is due to the ability of the individual fibers to slide against each other when deformed, resulting in improved formability of fabrics made from rCF yarns, enabling the draping of much more complex structures. This study aims to develop and characterize woven fabrics based on previous studies of rCF yarns for thermoset composites. In order to investigate staple fiber-spun yarns, a previous micro-scale modeling approach is extended. The formability of fabrics made from those rCF yarns is investigated through experimental forming tests and meso-scale simulations. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

16 pages, 12954 KiB

Open AccessArticle

A Study on the Charging–Discharging Mechanism of All Solid-State Aluminum–Carbon Composite Secondary Batteries

by Jia-Ying Lin, Bo-Ding Wu and Fei-Yi Hung

J. Compos. Sci. 2025, 9(4), 166; https://doi.org/10.3390/jcs9040166 - 29 Mar 2025

Viewed by 495

Abstract

Aluminum solid-state batteries are emerging as one of the most promising energy storage systems, offering advantages such as low cost and high safety. This study adopts a safe and cost-effective approach by alloying and doping the all-solid-state aluminum-ion battery to enhance its electrochemical [...] Read more.

Aluminum solid-state batteries are emerging as one of the most promising energy storage systems, offering advantages such as low cost and high safety. This study adopts a safe and cost-effective approach by alloying and doping the all-solid-state aluminum-ion battery to enhance its electrochemical performance. This research further explores the electrochemical impacts of these modifications on the performance of solid-state aluminum batteries. In this experiment, aluminum-based anodes were deposited onto nickel foil using the thermal evaporation (TE) method. At the same time, the graphite film (GF) cathode material was enriched with sodium (GFN) through a solution-based process. The system was combined with magnesium silicate solid electrolytes to investigate the all-solid-state aluminum-carbon battery′s structural characteristics and charge–discharge mechanisms. The experimental results demonstrate that the aluminum-coated electrode alloying effects and the graphite film modification significantly improve battery performance. The system achieved a maximum specific capacity of approximately 700 mAh g⁻¹, with a cycle life exceeding 100 cycles. Furthermore, the microstructural characteristics and phase structure of the aluminum evaporation film were confirmed. Analysis of ion transport pathways during the charge–discharge cycles of the all-solid-state aluminum-carbon battery revealed that both aluminum and magnesium ions play critical roles in the electrode processes. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

Review

Jump to: Research, Other

24 pages, 10292 KiB

Open AccessReview

Improving Surface Roughness of FDM-Printed Parts Through CNC Machining: A Brief Review

by Mauro Carta, Gabriela Loi, Mohamad El Mehtedi, Pasquale Buonadonna and Francesco Aymerich

J. Compos. Sci. 2025, 9(6), 296; https://doi.org/10.3390/jcs9060296 - 8 Jun 2025

Abstract

Fused Deposition Modeling (FDM) has evolved from a rapid prototyping technique to an established manufacturing process for various industrial applications, including aerospace, robotics, biomedical engineering, and food production. Despite its versatility, the surface quality and dimensional accuracy of FDM-printed parts remain significant challenges, [...] Read more.

Fused Deposition Modeling (FDM) has evolved from a rapid prototyping technique to an established manufacturing process for various industrial applications, including aerospace, robotics, biomedical engineering, and food production. Despite its versatility, the surface quality and dimensional accuracy of FDM-printed parts remain significant challenges, limiting their applicability in high-performance and precision-driven industries. Some of the primary limitations of FDM are volumetric error, shape deviation, and surface roughness, which directly affect the mechanical properties and functional performance of printed components. Post-processing techniques are available to mitigate these problems. Among the available post-processing techniques, CNC machining has emerged as a viable solution for improving the surface finish and dimensional precision of FDM parts. The integration of subtractive CNC machining with additive FDM printing enables the development of hybrid manufacturing strategies, leveraging the design freedom of 3D printing while ensuring superior surface quality. This paper presents a comprehensive review of recent studies on CNC post-processing of FDM-printed parts, analyzing its impact on surface roughness, dimensional accuracy, and material properties. Additionally, key process parameters influencing the effectiveness of CNC machining are discussed. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

27 pages, 4956 KiB

Open AccessReview

Recent Advancements in Polypropylene Fibre-Reinforced 3D-Printed Concrete: Insights into Mix Ratios, Testing Procedures, and Material Behaviour

by Ben Hopkins, Wen Si, Mehran Khan and Ciaran McNally

J. Compos. Sci. 2025, 9(6), 292; https://doi.org/10.3390/jcs9060292 - 6 Jun 2025

Viewed by 205

Abstract

This review presents a comprehensive analysis of polypropylene (PP) fibre incorporation in three-dimensional printed concrete (3DPC), focusing on the material behaviour in both fresh and hardened states. PP fibres play a critical role in improving rheological properties such as buildability, flowability, and extrudability. [...] Read more.

This review presents a comprehensive analysis of polypropylene (PP) fibre incorporation in three-dimensional printed concrete (3DPC), focusing on the material behaviour in both fresh and hardened states. PP fibres play a critical role in improving rheological properties such as buildability, flowability, and extrudability. While increased fibre content enhances interlayer bonding and shape retention through the fibre bridging mechanism, it also raises yield stress and viscosity, which may compromise extrudability. In the hardened state, PP fibres contribute to improvements in compressive and flexural strength up to an optimal dosage, beyond which performance may decline due to fibre clustering and reduced packing density. When aligned with the printing direction, fibres are particularly effective in mitigating shrinkage-induced cracking by redistributing internal tensile stress. However, their inclusion can lead to a slight increase in porosity and promote mechanical anisotropy. This review also discusses mix design parameters, fibre characteristics, and experimental protocols, while identifying key research gaps including the lack of standardized testing methods, limited understanding of fibre orientation effects, and insufficient exploration of hybrid fibre systems. Based on the synthesis of reported studies, optimal print quality and structural consistency have been associated with the use of 6 mm long fibres, nozzle diameters of 4 to 6 mm, and printing speeds ranging from 40 to 60 mm/s. Overall, PP fibre reinforcement shows strong potential for enhancing the structural integrity and dimensional stability of 3D-printed concrete, while emphasizing the need for further studies to optimize its use in practice. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

Other

Jump to: Research, Review

17 pages, 1730 KiB

Open AccessSystematic Review

The Impact of Sports Drink Exposure on the Surface Roughness of Restorative Materials: A Systematic Review

by Filip Podgórski, Wiktoria Musyt and Kacper Nijakowski

J. Compos. Sci. 2025, 9(5), 234; https://doi.org/10.3390/jcs9050234 - 5 May 2025

Viewed by 440

Abstract

The impact of acidic beverages on dental restorative materials, such as composites and glass ionomers, is critical in conservative dentistry. Exposure to an acidic environment can lead to the degradation of these materials, affecting their durability and clinical effectiveness. We aimed to examine [...] Read more.

The impact of acidic beverages on dental restorative materials, such as composites and glass ionomers, is critical in conservative dentistry. Exposure to an acidic environment can lead to the degradation of these materials, affecting their durability and clinical effectiveness. We aimed to examine the effect of sports drink exposure on the surface roughness of composite and glass ionomer materials. This systematic review was conducted based on the records published from 1 January 2005 to 31 December 2024, according to PRISMA statement guidelines, using the databases PubMed, Scopus, Web of Science, and Embase. Following the inclusion and exclusion criteria, 10 studies were included in this review and 6 in the meta-analysis. Meta-analysis demonstrated a statistically significant increase in surface roughness (Ra parameter) for glass ionomer materials after immersion in sports drinks for one week and one month. No such significant differences were observed for composite materials. Despite the systematic review, the degree of material degradation presented by in vitro studies cannot be directly extrapolated to oral conditions due to factors such as the buffering capacity of saliva or irregular exposure times to sports drinks. Full article

(This article belongs to the Special Issue Feature Papers in Journal of Composites Science in 2025)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Feature Papers in Journal of Composites Science in 2025

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (15 papers)

Research

Review

Other

Further Information

Guidelines

MDPI Initiatives

Follow MDPI