Special Issue "Surface Treatment of Metals"

A special issue of Coatings (ISSN 2079-6412).

Deadline for manuscript submissions: closed (30 June 2021).

Special Issue Editor

Prof. Dr. Petricǎ Vizureanu
E-Mail Website
Guest Editor
Departamentul de Tehnologii şi Echipamente pentru Procesarea Materialelor, Universitatea Tehnica Gh. Asachi din IasI, Iasi, Romania
Interests: material processing engineering; heat treatment; corrosion; hard coating; biomedical and aeronautical application
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Special Issue Information

Dear Colleagues,

We would like to invite you to submit your work to this Special Issue on “Surface Treatment of Metals”. The scope of this Special Issue includes surface treatment solutions applied for metallic materials which are cost-effective, energy-efficient, and safe for operators and the environment. The aim of this Special Issue is to present the latest experimental and theoretical achievements in the field, through a combination of original research papers and review articles from leading research groups around the world. Scientific and technological progress has been achieved on this topic by universities and research institutes worldwide. Further, surface coating is very well known by scientists and can improve the properties of any kind of metallic materials.

In particular, the topics of interest include but are not limited to:

  • Mechanical coating/alloying/treatment of the metals;
  • Heat/Thermo/chemical treatment of the metals;
  • Nonconventional treatment applied to metals, such as: thermo/mechanical coating, including removing of the heavy metals from industrial waste, electrochemical machining, abrasive flow machining, shot blasting, shot peening, turbo-abrasive machining, centrifugal barreling finish, centrifugal isotropic finishing, etc.;
  • Biomaterials coatings applied but not limited to Ti-based alloys, CoCr alloys, stainless steels.
In addition, The 7th edition of ICIR EUROINVENT will be held from 20 to 21 of May 2021. The authors of the papers that will be presented at ICIR Euroinvent 2021 are invited to submit their extended versions to this Special Issue after the conference. Submitted papers should be extended to the size of regular research or review articles, with at least a 50% extension of new results.
 

Prof. Dr. Petricǎ Vizureanu
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Coatings is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (8 papers)

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Research

Article
Effect of Electromigration and Thermal Ageing on the Tin Whiskers’ Formation in Thin Sn–0.7Cu–0.05Ga Lead (Pb)-Free Solder Joints
Coatings 2021, 11(8), 935; https://doi.org/10.3390/coatings11080935 - 04 Aug 2021
Viewed by 497
Abstract
The investigation on tin (Sn) whiskers formation has been widely applied in the field of lead-free electronic packaging. This is due to the fact that use of the Sn–Pb finishes has converted to Pb-free finishes in the electronic industry. Sn whiskers can grow [...] Read more.
The investigation on tin (Sn) whiskers formation has been widely applied in the field of lead-free electronic packaging. This is due to the fact that use of the Sn–Pb finishes has converted to Pb-free finishes in the electronic industry. Sn whiskers can grow long enough to cause a short circuit, which affects electronic devices’ reliability. This study investigates Sn whiskers’ formation in the thin Sn–0.7Cu–0.05Ga Pb-free solder under the influence of electromigration and thermal ageing for surface finish applications. The samples were stored in ambient conditions for 1000 h before being exposed to electromigration and thermal ageing to study the corresponding whiskers’ growth. A scanning electron microscope (SEM) was used to study the Sn whiskers’ microstructure, while an optical microscope (OM) was utilized to investigate the IMC layers in the samples. The results show that the addition of 0.05 wt.% gallium (Ga) decreased the Sn whisker’s length and growth density while simultaneously refining the IMC layers. Synchrotron micro-XRF (µ-XRF) shows the existence and distribution of Ga addition in both electromigration and thermal ageing samples. The shear test was used to determine the solder alloys’ mechanical properties. As a result, the addition of Ga to the Sn–0.7Cu solder improved the fracture morphology of solder joints. In conclusion, Ga’s addition resulted in decreasing Sn whisker formation and refining of the IMCs while also increasing the shear strength of the Sn–0.7Cu solder by ~14%. Full article
(This article belongs to the Special Issue Surface Treatment of Metals)
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Article
Study of the Spatial Distribution of Forces and Stresses on Wear Surfaces at Optimization of the Excavating Part of an Earthmoving Machine Transverse Profile
Coatings 2021, 11(2), 182; https://doi.org/10.3390/coatings11020182 - 04 Feb 2021
Cited by 1 | Viewed by 394
Abstract
The relevance of this research lies in the need to develop a scientifically-grounded methodology for designing the optimal profile of the contact frontal surface of an energy-efficient earthmoving machine operating device, which ensures the redistribution of resistance forces along the cutting elements during [...] Read more.
The relevance of this research lies in the need to develop a scientifically-grounded methodology for designing the optimal profile of the contact frontal surface of an energy-efficient earthmoving machine operating device, which ensures the redistribution of resistance forces along the cutting elements during the excavation of frozen soil when extracting hydrocarbons. The relevance is confirmed by the need to improve domestic methods for designing the profiles of effective operating devices, ensuring the excavation of frozen soils during the laying of oil and gas pipelines and geological exploration in permafrost areas. Increasing the energy efficiency and service life of highly loaded ripper teeth is done by optimizing the geometric profile and designing a spatial shape that provides minimal resistance to cutting the soil. The object of the research is the process of dynamic interaction of the ripper tooth cutting profile with the frozen soil environment. The research method used was kinematic analysis and force calculation. The cyclic process of dynamic loading of the ripper operating device was investigated. The methodology of system analysis, as well as the method of distribution of resistance forces over the geometric elements of the cutting edge, were used. The mathematical apparatus has been effectively applied to establish the dependences of the change in energy and power properties on performance indicators, soil rheology, and dynamic loads of the ripper tooth. The process of interaction of the ripper tooth tip with frozen soil was investigated. A method for substantiating the design parameters of the operating device by using Legendre polynomials was proposed. Separate calculation results subject to the introduced restrictions were presented for the condition for solving the problem. The optimal parameters of the transverse profile of the contact frontal surface of the earth-moving machine operating device were determined taking into account the coefficient of reducing the fracture resistance of frozen soils. Full article
(This article belongs to the Special Issue Surface Treatment of Metals)
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Article
Microstructural Analysis and Tribological Behavior of Ti-Based Alloys with a Ceramic Layer Using the Thermal Spray Method
Coatings 2020, 10(12), 1216; https://doi.org/10.3390/coatings10121216 - 12 Dec 2020
Cited by 3 | Viewed by 676
Abstract
The present article focuses on a recently developed new system of alloys (Ti15MoSi) coated with ZrO2. The thin coatings deposition of ZrO2 on titanium alloys can be a solution to improve their corrosion resistance, biocompatibility, and to extend their long [...] Read more.
The present article focuses on a recently developed new system of alloys (Ti15MoSi) coated with ZrO2. The thin coatings deposition of ZrO2 on titanium alloys can be a solution to improve their corrosion resistance, biocompatibility, and to extend their long life with the human tissue. In order to improve the corrosion resistance, atmospheric plasma spraying coatings with zirconia have been performed. These coatings present a homogenous aspect with very few cracks. The novelty of the research is that zirconia is much stable in the simulated body fluids and presents no harm effects to the healing process of the bone. To analyze the thin coatings deposition, mechanical properties, chemical structure, and corrosion resistance were examined by a modulus of elasticity, X-ray diffraction (XRD), scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDS), and linear polarization. The results reveal that Young’s modulus shows a low value (51 GPa for Ti15Mo0.5Si-ZrO2 and 48 GPa for Ti15Mo-ZrO2) and the XRD patterns show the presence of β-Ti and ZrO2 phases having a tetragonal crystalline structure. The research highlighted the morphological aspect of zirconia coatings on the new alloy titanium substrate, being an adherent compact coating with significantly improved corrosion resistance. Moreover, the mechanical properties are similar to the biological bone, which will avoid the stress shielding of the implant with bone tissue. Full article
(This article belongs to the Special Issue Surface Treatment of Metals)
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Article
Microstructural Analysis and Tribological Behavior of AMDRY 1371 (Mo–NiCrFeBSiC) Atmospheric Plasma Spray Deposited Thin Coatings
Coatings 2020, 10(12), 1186; https://doi.org/10.3390/coatings10121186 - 04 Dec 2020
Cited by 1 | Viewed by 563
Abstract
Water treatment plants include a set of pumping stations, and their mechanical components experience various wear modes. In order to combat wear, the mechanical components of the pumps are coated with various types of wear resistant coatings. In this research, AMDRY 1371 (Mo–NiCrFeBSiC) [...] Read more.
Water treatment plants include a set of pumping stations, and their mechanical components experience various wear modes. In order to combat wear, the mechanical components of the pumps are coated with various types of wear resistant coatings. In this research, AMDRY 1371 (Mo–NiCrFeBSiC) coatings were deposited with the atmospheric plasma spray (APS) method on parallelepipedal steel samples manufactured from a worn sleeve of a multistage vertical irrigation pump. In order to find an optimum thickness of AMDRY 1371 coatings, the samples were coated with five, seven and nine passes (counted as return passes of the APS gun). Mechanical properties of the coating (microhardness and Young’s modulus) were determined by micro-indentation tests. An AMSLER tribometer was used to investigate the wear resistance and wear modes of the coated samples in dry conditions. A mean coefficient of friction (CoF) of around 0.3 was found for all the samples, but its evolution during the one hour of the test and also the final wear volumes and wear rates depended on the thickness of the coating. To estimate the roughness of the surfaces and the wear volumes, measurements were carried out on a Taylor Hobson profilometer. In order to understand the nature and evolution of wear of coatings of various thicknesses, the unworn and worn surfaces of the coated samples were analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The wear modes of the coatings were studied, emphasizing the coating removal process for each sample. According to our results, for each dry friction application, there is an optimum value of the thickness of the coating, depending on the running conditions. Full article
(This article belongs to the Special Issue Surface Treatment of Metals)
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Article
On the Electrical and Optical Properties Stability of P3HT Thin Films Sensitized with Nitromethane Ferric Chloride Solutions
Coatings 2020, 10(11), 1074; https://doi.org/10.3390/coatings10111074 - 07 Nov 2020
Cited by 1 | Viewed by 714
Abstract
The electrical and optical properties stability of poly(3-hexylthiophene) (P3HT) thin films sensitized with nitromethane ferric chloride (FeCl3) solution was investigated. The optical properties modifications were studied by spectrophotometry and ellipsometry. For electrical characterizations, electrical resistivity measurements were performed. In agreement with [...] Read more.
The electrical and optical properties stability of poly(3-hexylthiophene) (P3HT) thin films sensitized with nitromethane ferric chloride (FeCl3) solution was investigated. The optical properties modifications were studied by spectrophotometry and ellipsometry. For electrical characterizations, electrical resistivity measurements were performed. In agreement with the observations of other authors, an important decrease in the electrical resistivity by six orders of magnitude was noticed. In addition, the repeatability and stability of this phenomenon were investigated over a few weeks after sensitization and during different cycles of heating and cooling, both in the dark and under illumination. Full article
(This article belongs to the Special Issue Surface Treatment of Metals)
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Article
The Effect of Temperature Distribution during Laser Heat Treatment of Gas-Nitrided 42CrMo4 Steel on the Microstructure and Mechanical Properties
Coatings 2020, 10(9), 824; https://doi.org/10.3390/coatings10090824 - 26 Aug 2020
Cited by 1 | Viewed by 876
Abstract
A gas-nitrided layer was produced on the toughened 42CrMo4 low-alloy steel using the changeable nitriding potential in order to limit the thickness of a brittle ε zone. The microstructure consisted of the compound ε + (ε + γ’) zone and diffusion zone (nitric [...] Read more.
A gas-nitrided layer was produced on the toughened 42CrMo4 low-alloy steel using the changeable nitriding potential in order to limit the thickness of a brittle ε zone. The microstructure consisted of the compound ε + (ε + γ’) zone and diffusion zone (nitric sorbite with γ’ precipitates). Such a layer was subjected to laser heat treatment with or without remelting. The single laser tracks were formed using various laser beam powers (in the range of 0.234–0.624 kW) and scanning rates (in the range of 2.24–3.84 m·min−1) and the same laser beam diameter (2 mm). The microstructure of laser-modified nitrided layer usually consisted of re-melted zone (MZ) with coarse-grained nitric martensite Feα’ and possible ε precipitates, heat-affected zone (HAZ) with fine-grained nitric martensite Feα’ and γ’ precipitates and diffusion zone with nitric sorbite and γ’ precipitates. Sometimes, the compound zone was partially re-melted and an amount of iron nitrides remained in the MZ. Only one laser track was characterized by the different microstructure, consisting of the compound ε + (ε + γ’) zone, HAZ with fine-grained nitric martensite Feα’ and γ’ precipitates and diffusion zone with nitric sorbite and γ’ precipitates. This laser track was formed without visible effects of remelting. The effect of temperature distribution during laser heat treatment of gas-nitrided 42CrMo4 steel on the microstructure and mechanical properties was studied. The equations developed by Ashby and Esterling were used in order to determine the temperature distribution along the axis of each laser track. Taking into account the temperature profiles, it was possible to calculate the depths of MZ and HAZ. These predicted values were compared to those-measured based on the microstructure observations, obtaining good compatibility. The microstructure of the produced surface layers influenced the mechanical properties such as hardness and Young’s modulus. The hardness of MZ was higher than that of ε zone and lower than that of ε + γ’ zone when compared to nitrided layer. Whereas Young’s modulus of MZ was significantly higher than those characteristic of the compound zone in gas-nitrided layer (both ε and ε + γ’ zone) and similar to that of HAZ. The laser heat treatment (LHT) without remelting resulted in the similar hardness and slightly higher Young’s modulus of ε zone in comparison with the nitrided layer. Simultaneously, such a treatment of the nitrided layer did not influence the hardness and the Young’s modulus of ε + γ’ zone considerably. The hardness of HAZ was higher than that of MZ and that of the same area of diffusion zone in the nitrided layer because of the presence of fine-grained nitric martensite with γ’ precipitates after laser quenching. Full article
(This article belongs to the Special Issue Surface Treatment of Metals)
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Article
Control of the Mg-Treated Iron Casting Skin Formation by S-Diffusion Blocking at the Metal–Mould Interface
Coatings 2020, 10(7), 680; https://doi.org/10.3390/coatings10070680 - 15 Jul 2020
Cited by 1 | Viewed by 789
Abstract
Having established that sulphur presence in the mould materials appears to have an important contribution in graphite degeneration at least in the casting surface layer, a research program is undertaken to explore the possible beneficial effect of sulphur diffusion blocking at the metal–mould [...] Read more.
Having established that sulphur presence in the mould materials appears to have an important contribution in graphite degeneration at least in the casting surface layer, a research program is undertaken to explore the possible beneficial effect of sulphur diffusion blocking at the metal–mould interface. Test samples, with and without a thin steel sheet (up to 3 mm thickness) application on the inner surface of the mould cavity, before iron melt pouring, are considered for structure analysis. A higher nodulizing potential (0.048% Mgres, 0.015% Ceres, and 0.006% Lares) decreases the occurrence of surface graphite degeneration in castings obtained in rigid chemically bonded resin sand moulds, using P-toluol sulfonic acid (PTSA) hardener (S-including), but it is not enough to avoid this phenomenon (200–400 μm skin in present experimental conditions). The casting skin appears to have different values, depending on the evaluation technique (un- and Nital-etching direct measurement, or graphite parameters variation on the casting section). In the presence of a thin steel sheet at the metal–mould interface, the casting skin thickness decreases or is just excluded. It is supposed that it acts as a barrier, blocking S-diffusion from the mould media into the iron melt. Without this S-diffusion, the graphite degeneration in the casting surface layer could be avoided, or at least diminished. For industrial application, the increasing of residual content of nodulizing elements is a limited solution, and it is recommended to use barriers to block S transfer on the mould/metal surface, such as dense coatings or coatings with desulphurization capacity. Full article
(This article belongs to the Special Issue Surface Treatment of Metals)
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Article
Improvement of the Turbine Blade Surface Phase Structure Recovered by Plasma Spraying
Coatings 2020, 10(1), 62; https://doi.org/10.3390/coatings10010062 - 10 Jan 2020
Cited by 4 | Viewed by 978
Abstract
This paper presents the results of research on the construction, technological parameters and criteria that control the process of formation of optimal phase structure of austenitic- and martensitic-class material for steam turbine blades. The hypothesis that the established correlation could increase the quality [...] Read more.
This paper presents the results of research on the construction, technological parameters and criteria that control the process of formation of optimal phase structure of austenitic- and martensitic-class material for steam turbine blades. The hypothesis that the established correlation could increase the quality of blade recovery and its resistance against dynamic and vibrational loads was proved. The efficiency of the developed implantation method for the recovery of steam turbine blades was demonstrated. The optimal technological parameters of the process of laser plasma recovery were established empirically, allowing the development of the system for the fine tuning of the phase composition of austenitic- and martensitic-class steel. Full article
(This article belongs to the Special Issue Surface Treatment of Metals)
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