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20 pages, 17195 KiB

Open AccessArticle

Optimization of Black Nickel Coatings’ Electrodeposit onto Steel

by Gabriel Santos, Zohra Benzarti, Diogo Cavaleiro, Luís Figueiredo, Sandra Carvalho and Susana Devesa

Coatings 2024, 14(9), 1125; https://doi.org/10.3390/coatings14091125 - 2 Sep 2024

Viewed by 406

Abstract

Coatings can be created using various technologies and serve different roles, including protection, functionality, and decorative purposes. Among these technologies, electrodeposition has emerged as a low-cost, versatile, and straightforward process with remarkable scalability and manufacturability. Nickel, extensively studied in the context of electrodeposition, [...] Read more.

Coatings can be created using various technologies and serve different roles, including protection, functionality, and decorative purposes. Among these technologies, electrodeposition has emerged as a low-cost, versatile, and straightforward process with remarkable scalability and manufacturability. Nickel, extensively studied in the context of electrodeposition, has many applications ranging from decorative to functional. The main objective of the present work is the electrodeposition of double-layer nickel coatings, consisting of a bright nickel pre-coating followed by a black nickel layer with enhanced properties, onto steel substrates. The influence of deposition parameters on colour, morphology, adhesion, roughness, and coefficient of friction was studied. The effects of cetyltrimethylammonium bromide (CTAB) and WS₂ nanoparticles on the coatings’ properties and performance were also investigated. Additionally, the influence of the steel substrate’s pre-treatment, consisting of immersion in an HCl solution, prior to the electrodeposition, to etch the surface and activate it, was evaluated and optimized. The characterization of the pre-coating revealed a homogeneous surface with a medium superficial feature of 2.56 μm. Energy dispersive X-ray spectroscopy (EDS) results showed a high content of Ni, and X-ray diffraction (XRD) confirmed its crystallinity. In contrast, the black films’ characterization revealed their amorphous nature. The BN10 sample, which corresponds to a black nickel layer with a deposition time of 10 min, showed the best results for colour and roughness, presenting the lowest brightness (L*) value (closest to absolute black) and the most homogeneous roughness. EDS analysis confirmed the incorporation of WS₂, but all samples with CTAB exhibited signs of corrosion and cracks, along with higher coefficient of friction (COF) values. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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15 pages, 4336 KiB

Open AccessArticle

Microstructure and Wear Performance of TaC and Ta/TaC Coatings on 30CrNi2MoVA Steel

by Kai Yang, Xuming Lv, Bo Dang, Zhuoyan Lai, Xiaohu Chen, Dongbo Wei, Shuqin Li and Pingze Zhang

Coatings 2024, 14(8), 1039; https://doi.org/10.3390/coatings14081039 - 15 Aug 2024

Viewed by 482

Abstract

To enhance the wear resistance of artillery barrels in harsh environments, TaC and Ta/TaC coatings were prepared on 30CrNi2MoVA steel using double-glow plasma surface metallurgy technology. These coatings, of which their surfaces consisted of almost pure TaC phases, showed defect-free interfaces with the [...] Read more.

To enhance the wear resistance of artillery barrels in harsh environments, TaC and Ta/TaC coatings were prepared on 30CrNi2MoVA steel using double-glow plasma surface metallurgy technology. These coatings, of which their surfaces consisted of almost pure TaC phases, showed defect-free interfaces with the substrate. The Ta/TaC coating demonstrated excellent integration, forming a nearly homogeneous structure. The coatings exhibited a gradient cross-sectional hardness, affecting a depth of approximately 20 μm. The Ta transition layer significantly enhanced the microhardness and adhesive strength of the TaC coating, with about 16.7% and 68.5% increases in the Ta/TaC coating, respectively. Both coatings markedly improved the wear resistance, showing slight wear at room temperature and minor oxidative wear at high temperatures. The Ta/TaC coating had more stable friction coefficient curves and a lower specific wear rate, with an 11.4% wear rate of the substrate at 500 °C. Thermal mismatch and stress concentration under wear loads caused extensive cracks and edge chipping in the TaC coating. In contrast, the good compatibility between the Ta transition layer and the TaC layer allowed for cooperative deformation with the substrate, creating a plastic deformation zone that reduced internal stresses and stress concentration, maintaining the intact structure. This study provides insights into applying Ta/TaC coatings for artillery barrel protection and broadens the possible application scenarios of the preparation technology. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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18 pages, 12340 KiB

Open AccessArticle

High-Temperature Mechanical and Tribological Performance of W-DLC Coating with Cr interlayer on X40CrMoV5-1 Hot Work Tool Steel

by Mária Hagarová, Gabriela Baranová, Mária Heželová, Martin Truchlý, Marek Vojtko, Ondrej Petruš and Dávid Csík

Coatings 2024, 14(8), 971; https://doi.org/10.3390/coatings14080971 - 2 Aug 2024

Viewed by 646

Abstract

Diamond-like carbon (DLC) coatings enhance tool wear resistance across various temperatures. The sp³/sp² bond ratio within DLC significantly impacts its properties and thermal stability. Elevated temperatures can alter DLC’s structure, while metallic elements and interlayers like chromium can modify its [...] Read more.

Diamond-like carbon (DLC) coatings enhance tool wear resistance across various temperatures. The sp³/sp² bond ratio within DLC significantly impacts its properties and thermal stability. Elevated temperatures can alter DLC’s structure, while metallic elements and interlayers like chromium can modify its microstructure and performance. To evaluate the potential of W-DLC coatings with a chromium interlayer on 40CrMoV5-1 hot work tool steel under elevated temperatures, mechanical and tribological properties were assessed at room temperature and at temperatures of 100, 200, 300, 400, and 500 °C. Nanoindentation revealed a maximum hardness of 14.1 ± 1.3 GPa for the coating deposited at room temperature, attributed to a high sp³ content confirmed by Raman spectroscopy. Hardness decreased to 9.3 ± 1.0 GPa at 400 °C due to graphitization. The elastic modulus remained relatively constant across all temperatures. Tribological tests indicated a low coefficient of friction (CoF) of 0.15 at room temperature, increasing to 0.35 at 100 °C. The CoF further rose to 0.5 at 200 °C, coinciding with increased graphitization. However, the CoF reduced to 0.45 and 0.35 at 400 °C and 500 °C, respectively, likely due to the formation of a WO₃ tribo-film and the protective effect of the chromium interlayer. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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16 pages, 2738 KiB

Open AccessArticle

Investigation of the Influence of Including or Omitting the Oxide Layer on the Result of Identifying the Local Boundary Condition during Water Spray Cooling

by Agnieszka Cebo-Rudnicka and Beata Hadała

Coatings 2024, 14(7), 884; https://doi.org/10.3390/coatings14070884 - 16 Jul 2024

Viewed by 551

Abstract

In the case of products made of steel, the presence of an oxide layer, which is formed during the steel production process as a result of high temperature, has a significant impact on the process of heat removal from the surface of the [...] Read more.

In the case of products made of steel, the presence of an oxide layer, which is formed during the steel production process as a result of high temperature, has a significant impact on the process of heat removal from the surface of the cooled material. For this reason, it is necessary to take into account the presence of the oxide layer in mathematical and numerical models used to simulate the distribution of the temperature field in cooled steel products. These models are based on the boundary conditions identified for given production conditions. This paper presents a comparison of the results of the identification of the boundary condition during water spray cooling of Armco iron with the use of the inverse solution. Numerical calculations were carried out using two models of heat conduction. In the first model, the presence of an oxide layer with different thermophysical properties than the base material (Armco iron) was taken into account. The second model assumed no oxide layer on the cooled Armco iron surface. It was found that the inverse solution obtained in the case of the heat conduction model taking into account the thickness of the oxide layer is correct in time and as a function of temperature. Thus, the boundary condition model obtained as a function of temperature is universal. However, this model requires an additional layer of oxides with different thermophysical properties than the base material to be included in the finite element model (FEM). Based on the conducted uncertainty tests of the inverse solution, it was found that the results of the determined boundary condition in the absence of the oxide layer on the cooled surface are subject to an error higher than 10% in comparison to the maximum reference value of the heat transfer coefficient. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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15 pages, 28154 KiB

Open AccessArticle

Study on the Cutting Performance and Remaining Life Prediction of Micro-Texture Ball End Milling Cutters for Titanium Alloys

by Yuhua Zhang, Yongqi Fu, Quanxi Li, Keyi Zhang and Kuo Liu

Coatings 2024, 14(7), 814; https://doi.org/10.3390/coatings14070814 - 29 Jun 2024

Viewed by 596

Abstract

As a fundamental machining tool, the ball end milling cutter plays a crucial role in manufacturing. Due to its low thermal conductivity, the heat generated during the cutting process of titanium alloy materials is not dissipated efficiently, resulting in a substantial cutting heat. [...] Read more.

As a fundamental machining tool, the ball end milling cutter plays a crucial role in manufacturing. Due to its low thermal conductivity, the heat generated during the cutting process of titanium alloy materials is not dissipated efficiently, resulting in a substantial cutting heat. This heat leads to chip adhesion and exacerbates the wear of the ball end milling cutter, ultimately affecting its service life. Therefore, studying the residual life of the tool during the cutting process is essential to prevent significant impacts on the product’s surface quality due to tool damage and passivation. Most research on micro-texture cutters is based on experiments that analyze the wear patterns of cutters under various lubrication conditions and their influence on the cutting process. Different neural network prediction models are employed to enhance the accuracy and stability of tool life prediction models. However, the exploration of other superior models for predicting the life of micro-texture cutters remains ongoing. This paper is based on an experiment involving the milling of titanium alloy using a micro-pit-structured ball end milling cutter. It was found that the cutting force of the tool is higher during the initial and later wear stages. During the stable wear stage, the unevenness of the defective layer on the tool surface is reduced, increasing the contact area and reducing the surface pressure, thereby decreasing the cutting force. This study analyzes the influence of micro-pit structural parameters on the wear and milling force of the ball end milling cutter. By evaluating the wear value of the ball end milling cutter after each cut, the wear mechanism of the micro-texture cutter is identified. A deep-learning-based bidirectional long short-term memory (BiLSTM) neural network model for tool life prediction is developed. Through training and validation, the model’s accuracy and stability are continuously improved. A comparative analysis with different predictive models is conducted to determine whether the proposed model offers advantages over existing models, which is crucial for maximizing tool utilization and reducing manufacturing costs. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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24 pages, 14580 KiB

Open AccessArticle

Design of Tool Wear Monitoring System in Bone Material Drilling Process

by Lijia Liu, Wenjie Kang, Yiwen Wang and Lingchen Zeng

Coatings 2024, 14(7), 812; https://doi.org/10.3390/coatings14070812 - 28 Jun 2024

Viewed by 655

Abstract

Biological bone materials, complex and anisotropic, require precise machining in surgeries. Bone drilling, a key technique, is susceptible to increased friction from tool wear, leading to excessive forces and high temperatures that can damage bone and surrounding tissues, affecting recovery. This study develops [...] Read more.

Biological bone materials, complex and anisotropic, require precise machining in surgeries. Bone drilling, a key technique, is susceptible to increased friction from tool wear, leading to excessive forces and high temperatures that can damage bone and surrounding tissues, affecting recovery. This study develops a monitoring platform to assess tool wear during bone drilling, employing an experimental setup that gathers triaxial force and vibration data. A recognition model using a bidirectional long short-term memory network (BI-LSTM) with a multi-head attention mechanism identified wear levels. This model, termed ABI-LSTM, was optimized and benchmarked against SVR, RNN, and CNN models. The results from implementing the ABI-LSTM-based monitoring system demonstrated its efficacy in detecting tool wear, thereby potentially reducing surgical risks such as osteonecrosis and drill breakage, and enhancing surgical outcomes. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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25 pages, 7832 KiB

Open AccessArticle

A Comparative Study on Al_0.6Ti_0.4N Coatings Deposited by Cathodic Arc and HiPIMS in End Milling of Stainless Steel 316L

by Victor Saciotto, Qianxi He, Monica C. Guimaraes, Jose M. DePaiva, Joern Kohlscheen, Luis C. Fontana and Stephen C. Veldhuis

Coatings 2024, 14(7), 811; https://doi.org/10.3390/coatings14070811 - 28 Jun 2024

Cited by 1 | Viewed by 859

Abstract

The machining of austenitic stainless steel alloys is usually characterized by high levels of adhesion and built-up edge; therefore, improving tribological conditions is fundamental to obtaining higher tool life and better surface finish. In this work, three different Al_0.6Ti_0.4N [...] Read more.

The machining of austenitic stainless steel alloys is usually characterized by high levels of adhesion and built-up edge; therefore, improving tribological conditions is fundamental to obtaining higher tool life and better surface finish. In this work, three different Al_0.6Ti_0.4N coatings are compared, two deposited by Cathodic Arc Evaporation (CAE) and one with High-Power Impulse Magnetron Sputtering (HiPIMS). The effects of the micromechanical properties and the microstructure of the coatings were then studied and related to the machining performance. Both arc-deposited coatings (CAE 1 and 2) exhibited similar average tool life, 127 min and 128 min, respectively. Whereas the HiPIMS lasted for only 21.2 min, the HiPIMS-coated tool had a much shorter tool life (more than six times lower than both CAE coatings) due to the intense adhesion that occurred in the early stages of the tool life. This higher adhesion ultimately caused built-up edge and chipping of the tool. This was confirmed by the cutting forces and more deformation on the shear band and undersurface of the chips, which are related to higher levels of friction. The higher adhesion could be attributed to the columnar structure of the HiPIMS and the (111) main texture, which presents a higher surface energy when compared to the dominant (200) from both arc depositions. Studies focused on tribology are necessary to further understand this relationship. In terms of micromechanical properties, tools with the highest plasticity index performed better (CAE 2 = 0.544, CAE 1 = 0.532, and HiPIMS = 0.459). For interrupted cutting machining where adhesion is the main wear mechanism, a reserve of plasticity is beneficial to dissipate the energy generated during friction, even if this was related to lower hardness levels (CAE 2 = 26.6 GPa, CAE 1 = 29.9 GPa, and HiPIMS = 33.6 GPa), as the main wear mechanism was adhesive and not abrasive. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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21 pages, 35091 KiB

Open AccessArticle

Analysis of Wear Vibration Behavior of Micro-Textured Coated Cemented Carbide Considering High-Order Scale

by Xin Tong and Shoumeng Wang

Coatings 2024, 14(7), 791; https://doi.org/10.3390/coatings14070791 - 25 Jun 2024

Viewed by 854

Abstract

In order to explore the influence of high-order micro-texture parameters on the friction, wear, and vibration characteristics of coated cemented carbide pin surfaces, expand the research field of textured coating modification processes. Firstly, a laser was used to prepare micro-texture on the surface [...] Read more.

In order to explore the influence of high-order micro-texture parameters on the friction, wear, and vibration characteristics of coated cemented carbide pin surfaces, expand the research field of textured coating modification processes. Firstly, a laser was used to prepare micro-texture on the surface of the cemented carbide pin, and AlCrN coating was carried out. The friction and wear test platform of the micro-textured physical vapor deposition (PVD)-coated cemented carbide and titanium alloy substrate was built, and the friction vibration and acoustic vibration signals were obtained as the main analysis media. Secondly, according to the characteristics of the test signal, three time-frequency images are analyzed and compared. The continuous wavelet transform (CWT) method with a better time-frequency analysis effect is selected. Finally, the characteristics and regularity of friction vibration and acoustic vibration are analyzed by using the gray mean of the CWT time-frequency image. The influence mechanism of high-order micro-texture parameters on the surface characteristics of coated cemented carbide pins was obtained. It is concluded that the high-order micro-texture is 1.58% higher than the traditional scale in the stability of friction vibration, 4.47% higher in the stability of acoustic vibration, and 13.16% lower in the friction force, which proves the progress of the size improvement. It provides a practical basis for the extension research of cemented carbide surface modification. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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22 pages, 16294 KiB

Open AccessArticle

Cutting Energy Consumption Modeling by Considering Tool Wear and Workpiece Material Properties for Multi-Objective Optimization of Machine Tools

by Yue Meng, Shengming Dong, Xinsheng Sun, Shiliang Wei and Xianli Liu

Coatings 2024, 14(6), 691; https://doi.org/10.3390/coatings14060691 - 1 Jun 2024

Viewed by 364

Abstract

The increasing demand for energy is leading to global depletion of fossil fuels and growing environmental pressures, which are issues that need to be addressed. Machine tools are basic energy-consuming equipment in manufacturing systems. However, existing theoretical models ignore tool wear as well [...] Read more.

The increasing demand for energy is leading to global depletion of fossil fuels and growing environmental pressures, which are issues that need to be addressed. Machine tools are basic energy-consuming equipment in manufacturing systems. However, existing theoretical models ignore tool wear as well as workpiece material properties. This makes it difficult to further improve the accuracy of the model. Therefore, this study begins with the point of view of energy dissipation in the metal material removal process. A milling power model for computer numerical control (CNC) machines, considering tool wear and workpiece material properties during machining, is established. At the same time, milling is taken as the research object. A multi-objective cutting parameter optimization model is established to ensure the surface quality of the workpiece. In addition, the cutting energy consumption is taken into account in the developed models. Based on the multi-objective manta ray foraging optimization algorithm (MOMRFO), the Pareto-optimal solution set under multiple cutting conditions is solved. Finally, the experimental results of optimized parameters are compared with empirical parameters. The average prediction accuracy of the proposed energy consumption prediction model is above 91%. The experiments show that machining quality improves by optimizing the cutting parameters, with SEC, MRR, and Ra increasing by more than 44%, 53%, and 38%, respectively. The goals of reducing energy consumption and increasing productivity are achieved. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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14 pages, 4059 KiB

Open AccessArticle

Experimental Study on Microwave Drying Aluminum Hydroxide

by Xuemei Zheng, Fuqin Yuan, Aiyuan Ma and Shihong Tian

Coatings 2024, 14(6), 687; https://doi.org/10.3390/coatings14060687 - 1 Jun 2024

Viewed by 596

Abstract

The aluminum hydroxide produced by the Bayer process contains a large amount of water which leads to the consumption of a large amount of heat for moisture removal in the calcination process, resulting in an increased energy consumption. The effects of temperature and [...] Read more.

The aluminum hydroxide produced by the Bayer process contains a large amount of water which leads to the consumption of a large amount of heat for moisture removal in the calcination process, resulting in an increased energy consumption. The effects of temperature and microwave power on the dehydration ratio and the dry matter ratio of aluminum hydroxide were investigated. The characteristics of temperature variation during drying were discussed. X-ray diffraction (XRD), scanning electron microscopy (SEM), laser particle size, Fourier transform infrared (FTIR) spectroscopy, and dielectric property analyses were made to characterize the dried materials. The analysis results showed that within the range of bench-scale experimental parameters, the dehydration ratio was higher and the proportion of dry matter was lower at a higher final temperature. Within the range of pilot-scale experimental parameters, the dehydration ratio increased with the increasing microwave power from 500 W to 1500 W. XRD spectra revealed that when the final temperature exceeded 220 °C, a part of the aluminum hydroxide underwent a low-temperature phase transition to boehmite. The SEM images and a particle size analysis showed that there was no significant difference between the morphologies of the powder obtained by microwave drying and conventional drying methods. The powder obtained by both processes had an average particle size of around 80 μm. The dielectric constant and the dielectric loss of the dried material decreased greatly. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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11 pages, 5128 KiB

Open AccessArticle

A Comparative Study of Machining Property in Inconel 718 Superalloy Grinding with Al₂O₃- and CBN/Fe-Based Spherical Magnetic Abrasives

by Linzhi Jiang, Guixiang Zhang, Haozhe Zhang, Yandan Xia and Jinli Xiang

Coatings 2024, 14(6), 686; https://doi.org/10.3390/coatings14060686 - 1 Jun 2024

Viewed by 356

Abstract

A comparative analysis was studied on the finishing performance of spherical CBN/Fe-based magnetic abrasive particles (MAPs) and Al₂O₃/Fe-based magnetic abrasive particles (MAPs) prepared by the gas atomization method in the magnetic abrasive finishing (MAF) of the Inconel 718 superalloy. [...] Read more.

A comparative analysis was studied on the finishing performance of spherical CBN/Fe-based magnetic abrasive particles (MAPs) and Al₂O₃/Fe-based magnetic abrasive particles (MAPs) prepared by the gas atomization method in the magnetic abrasive finishing (MAF) of the Inconel 718 superalloy. In the MAF, it was found that compared with Al₂O₃/Fe-based MAPs, CBN/Fe-based MAPs have a lower grinding temperature and generate less heat during the grinding of the Inconel 718 superalloy. The grinding pressure generated on the workpiece is relatively stable (Al₂O₃/Fe-based MAPs have a larger fluctuation range of grinding pressure on the workpiece surface during the grinding process). The surface roughness of the workpiece rapidly drops from Ra 0.57 μm to Ra 0.039 μm, and the material removal reaches 42 mg within 20 min. After finishing, the scratches on the surface of the workpiece basically disappear, the contour curve is relatively flat, and there is almost no adhesion on the surface of the workpiece. The mirror effect of the superalloy surface is good, and ultimately a better surface quality can be obtained. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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19 pages, 8022 KiB

Open AccessArticle

Analysis of Surface Characteristics of Titanium Alloy Milling with Ball-End Milling Cutters Based on Mesoscopic Geometric Features

by Xin Tong, Shoumeng Wang, Xiyue Wang and Qiang Qu

Coatings 2024, 14(6), 670; https://doi.org/10.3390/coatings14060670 - 25 May 2024

Viewed by 606

Abstract

In order to further reduce the height of burrs on the surface of the workpiece when milling titanium alloy with ball-end milling cutters and optimize the quality of the workpiece, this article takes the mesoscopic geometric feature of ball-end milling cutters as the [...] Read more.

In order to further reduce the height of burrs on the surface of the workpiece when milling titanium alloy with ball-end milling cutters and optimize the quality of the workpiece, this article takes the mesoscopic geometric feature of ball-end milling cutters as the research object and establishes the theoretical relationship between the mesoscopic geometric feature parameters and the height of titanium alloy burrs during milling. A milling test platform was built to explore the influence of micro-texture, blunt edge single factor, and their interaction with cutting parameters on the force-thermal characteristics and workpiece burr in the milling process. The influence mechanism was revealed, and the prediction model was established. The results show that the ball-end milling cutter with mesoscopic geometric features was able to suppress burrs, and the burr height was reduced by 21% compared with the non-textured milling cutter. The micro-texture reduced the contact area and improved the heat dissipation conditions, thereby reducing the force-thermal characteristics and thus inhibiting the formation of some burrs. The blunt edge can disperse the stress, diffuse the local heat in the tool–chip contact area, and reduce the burr height. In the interaction test considering cutting parameters, the interaction between R and ap was significant. The optimized parameters based on the simulated annealing algorithm were as follows: the radius of the blunt edge was 33.242 μm, the distance between the texture and the edge was 114.621 μm, the texture diameter was 59.820 μm, the texture spacing L₁ was 131.410 μm, the cutting depth a_p was 0.310 mm, the cutting speed V was 140.019 mm/min, and the feed f was 60 μm/z. This provides a basis for the study of strengthening the tool to suppress burr size. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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16 pages, 5663 KiB

Open AccessArticle

Uncovering the Effect of CeO₂ on the Microstructure and Properties of TiAl/WC Coatings on Titanium Alloy

by Xinmeng Sui, Yitao Weng, Lin Zhang, Jian Lu, Xiangbiao Huang, Fuquan Long and Weiping Zhang

Coatings 2024, 14(5), 543; https://doi.org/10.3390/coatings14050543 - 27 Apr 2024

Viewed by 873

Abstract

It remains a popular question whether rare earth oxides encourage reinforcing phases to the uniform distribution in cermet coating to improve the mechanical properties. This study applied laser cladding to prepare the TiAl/WC/CeO₂ MMC cermet coatings on the TC21 alloy substrate. The [...] Read more.

It remains a popular question whether rare earth oxides encourage reinforcing phases to the uniform distribution in cermet coating to improve the mechanical properties. This study applied laser cladding to prepare the TiAl/WC/CeO₂ MMC cermet coatings on the TC21 alloy substrate. The effects of CeO₂ content on the phase composition, microstructure formation, evolution mechanism, and properties of cermet coatings were investigated. Results show that the incorporation of CeO₂ did not change the phase of composite coating, but the shape of the TiC phase has a close relation to the CeO₂ content. CeO₂ enhanced the fluidity of the molten pool, which further encouraged the TiC/Ti₂AlC core-shell reinforcement phase. With the increase in CeO₂ content, the optimized coating contributed to homogenous microstructure distribution and fine grain size. Owing to the hard phases strengthening and dispersion strengthening effects of CeO₂, the microhardness of the composite coatings was all significantly higher (almost 1.6 times) than that of the substrate. Importantly, the addition of CeO₂ significantly improved the wear resistance of the composite coating. This work provides a certain reference value for the study of surface strengthening of key parts in the aerospace field. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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20 pages, 18484 KiB

Open AccessArticle

Effect of Low-Temperature Plasma Carburization on Fretting Wear Behavior of AISI 316L Stainless Steel

by Lu Sun, Yuandong Li, Chi Cao, Guangli Bi and Xiaomei Luo

Coatings 2024, 14(2), 158; https://doi.org/10.3390/coatings14020158 - 25 Jan 2024

Cited by 1 | Viewed by 1149

Abstract

AISI 316L stainless steel has received considerable attention as a common material for key ball valve components; however, its properties cannot be improved through traditional phase transformation, and fretting wears the contact interface between valve parts. A carburized layer was prepared on the [...] Read more.

AISI 316L stainless steel has received considerable attention as a common material for key ball valve components; however, its properties cannot be improved through traditional phase transformation, and fretting wears the contact interface between valve parts. A carburized layer was prepared on the surface of AISI 316L stainless steel by using double-glow low-temperature plasma carburization technology. This study reveals the effect of double-glow low-temperature plasma carburization technology on the fretting wear mechanism of AISI 316L steel under different normal loads and displacements. The fretting wear behavior and energy dissipation of the AISI 316L steel and the carburized layer were studied on an SRV-V fretting friction and wear machine with ball–plane contact. The wear mark morphology was analyzed by using scanning electron microscopy (SEM), the phase structure of the carburized layer was characterized with X-ray diffractometry (XRD), and the wear profile and wear volume were evaluated with laser confocal microscopy. The carburized layer contains a single Sc phase, a uniform and dense structure, and a metallurgically combined matrix. After plasma carburizing, the sample exhibited a maximum surface hardness of 897 ± 18 HV_0.2, which is approximately four times higher than that of the matrix (273 ± 33 HV_0.2). Moreover, the surface roughness was approximately doubled. The wear depth, wear rate, and frictional dissipation energy coefficient of the carburized layer were significantly reduced by up to approximately an order of magnitude compared with the matrix, while the wear resistance and fretting wear stability of the carburized layer were significantly improved. Under different load conditions, the wear mechanism of the AISI 316L steel changed from adhesive wear and abrasive wear to adhesive wear, fatigue delamination, and abrasive wear. Meanwhile, the wear mechanism of the carburized layer changed from adhesive wear to adhesive wear and fatigue delamination, accompanied by a furrowing effect. Under variable displacement conditions, both the AISI 316L steel and carburized layer mainly exhibited adhesive wear and fatigue peeling. Oxygen elements accumulated in the wear marks of the AISI 316L steel and carburized layer, indicating oxidative wear. The fretting wear properties of the AISI 316L steel and carburized layer were determined using the coupled competition between mechanical factors and thermochemical factors. Low-temperature plasma carburization technology improved the stability of the fretting wear process and changed the fretting regime of the AISI 316L steel and could be considered as anti-wearing coatings of ball valves. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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24 pages, 21778 KiB

Open AccessArticle

Uniform-Density Micro-Textured Ball-End Milling Cutter Model Based on Fractal and Uniform Distribution Theory

by Pei Han, Xin Tong, Shucai Yang and Xiyue Wang

Coatings 2023, 13(8), 1446; https://doi.org/10.3390/coatings13081446 - 16 Aug 2023

Cited by 1 | Viewed by 1126

Abstract

At present, for micro-textured tools, the determination of the micro-texture placement area depends on the derivation of the cutting geometric model. The micro-texture distribution form applies geometric methods, and the research methods and accuracy are limited. Therefore, in this paper, the ball-end milling [...] Read more.

At present, for micro-textured tools, the determination of the micro-texture placement area depends on the derivation of the cutting geometric model. The micro-texture distribution form applies geometric methods, and the research methods and accuracy are limited. Therefore, in this paper, the ball-end milling cutter is taken as the research object. Based on fractal theory, the morphology of the tool before and after wear is compared to determine the tool–chip contact area. The uniform-density micro-texture distribution model is established using the uniform distribution point theorem, and the synergistic mechanism of the edge and the micro-texture is revealed. The strength of the micro-textured tool with uniform density under the action of the edge is studied by simulation. Finally, the determination of the tool–chip contact area and the establishment of a uniform-density micro-texture model is realized. It is proved that the synergistic effect of the cutting edge and the micro-texture has a positive effect on the milling behavior of the tool. When comparing the non-edge and non-texture tools with the cutting-edge tools, the maximum strain and stress of the cutting-edge micro-textured tools increased by 12% and 30%, and 30% and 20%, respectively, without affecting the normal use of the tool. This research provides a new method for the design of micro-textured tools. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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20 pages, 14588 KiB

Open AccessFeature PaperArticle

Analysis of Physicochemical Properties of W1.8507 Steel Parts with Sharp Edges, Thermochemically Treated by Plasma Nitriding with and without Polarized Screens

by Mihai Axinte, Petrica Vizureanu, Nicanor Cimpoesu, Carmen Nejneru, Diana-Petronela Burduhos-Nergis and Elena-Luiza Epure

Coatings 2023, 13(1), 177; https://doi.org/10.3390/coatings13010177 - 13 Jan 2023

Cited by 1 | Viewed by 2090

Abstract

The plasma nitriding edge effect phenomenon is characteristic of parts with sharp edges. The intersection for the discharge of negative light of the two adjacent faces causes the apparition of this effect. In some cases, this effect causes disturbance to the general process. [...] Read more.

The plasma nitriding edge effect phenomenon is characteristic of parts with sharp edges. The intersection for the discharge of negative light of the two adjacent faces causes the apparition of this effect. In some cases, this effect causes disturbance to the general process. In this work, a sample with different angles of 30°, 60°, and 90° was analyzed. The sample was subjected to ion nitriding with and without the cathode grid to highlight the reduction of the edge effect on the non-uniformity appearing on the edges and corners of the parts. The effect of the active screen was also analyzed by hardness measurements in the area of the nitride edges and by SEM and EDX analyses in the mentioned areas. Additionally, the influence of active screens was studied by nanoindentation and scratch tests and by measuring the contact angle of coolants and liquid lubricants on the nitride surfaces with both methods. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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16 pages, 3930 KiB

Open AccessArticle

Controlling the Layer Thickness of Zinc Oxide Photoanode and the Dye-Soaking Time for an Optimal-Efficiency Dye-Sensitized Solar Cell

by Kaiswariah Magiswaran, Mohd Natashah Norizan, Norsuria Mahmed, Ili Salwani Mohamad, Siti Norhafizah Idris, Mohd Faizul Mohd Sabri, Nowshad Amin, Andrei Victor Sandu, Petrica Vizureanu, Marcin Nabiałek and Mohd Arif Anuar Mohd Salleh

Coatings 2023, 13(1), 20; https://doi.org/10.3390/coatings13010020 - 22 Dec 2022

Cited by 2 | Viewed by 2277

Abstract

Dye-sensitized solar cells (DSSCs) were developed by exploiting the photovoltaic effect to convert solar energy into electrical energy. The photoanode layer thickness significantly affects the semiconductor film’s ability to carry electronic charges, adsorb sensitizing dye molecules, and lower the recombination of photo-excited electrons [...] Read more.

Dye-sensitized solar cells (DSSCs) were developed by exploiting the photovoltaic effect to convert solar energy into electrical energy. The photoanode layer thickness significantly affects the semiconductor film’s ability to carry electronic charges, adsorb sensitizing dye molecules, and lower the recombination of photo-excited electrons injected into the semiconductor. This study investigated the dependence of the zinc oxide (ZnO) photoanode thin-film thickness and the film soaking time in N719 dye on the photocurrent–voltage characteristics. The ZnO photoanode was applied to glass using the doctor blade method. The thickness was varied by changing the scotch tape layers. The ZnO-based DSSC attained an efficiency of 2.77% with three-layered photoanodes soaked in the dye for three hours, compared to a maximum efficiency of 0.68% that was achieved with three cycles using the dip-coating method in other research. The layer thickness of the ZnO photoanode and its optimal adsorption time for the dye are important parameters that determine the efficiency of the DSSC. Therefore, this work provides important insights to further improve the performance of DSSCs. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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25 pages, 11085 KiB

Open AccessArticle

Influence of Fin Thickness on the Thermal Performance and Selection of Coating Method for a Bus Duct Conductor

by Mark Selvan, Mohd Sharizal Abdul Aziz, Mohd Arif Anuar Mohd Salleh, Nurulakmal Mohd Sharif, Chu Yee Khor, Heng Pin Ong, Mohd Remy Rozaini Mohd Arif Zainol, Petrica Vizureanu, Diana-Petronela Burduhos-Nergis and Andrei Victor Sandu

Coatings 2023, 13(1), 12; https://doi.org/10.3390/coatings13010012 - 22 Dec 2022

Cited by 1 | Viewed by 2733

Abstract

This paper studies the fin thickness variation effect on a bus duct conductor’s thermal performance and the nanocomposite coating method selection for the bus duct conductor’s heat sink. ANSYS FLUENT was used to create a numerical model resembling the experimental setup. The IEC [...] Read more.

This paper studies the fin thickness variation effect on a bus duct conductor’s thermal performance and the nanocomposite coating method selection for the bus duct conductor’s heat sink. ANSYS FLUENT was used to create a numerical model resembling the experimental setup. The IEC 60439-1 and IEC 60439-2 standards were used to benchmark the experimental data. The results revealed that the “chimney effect” induces an increment of the hot air adjacent to the heat sink. A conspicuous increase in the total heat transfer rate and fin effectiveness was observed as the fin thickness was reduced. This study revealed that s1 = 1 mm was the best fin thickness with 1.254 fin effectiveness, 1.862 W of total heat transfer rate, and 17.5 Nusselt number. Additionally, various coating methods were examined experimentally to select the best nanocomposite coating for the bus duct conductor’s heat sink. The ultrasonic agitation was the best coating method, which resulted in the lowest average resistance (8.8 μΩ) and a better percentage of Ag (0.6%–2.5%) on the substrate surface. Thus, the current outcomes are expected to better comprehend the impact of fin thickness on thermal performance, as well as the selection of coating method for the bus duct conductor. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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14 pages, 5458 KiB

Open AccessArticle

Mathematical Modeling and Experimental Validation of Surface Roughness in Ball Burnishing Process

by Rahul O. Vaishya, Vivek Sharma, Vinod Mishra, Anurag Gupta, Mandeep Dhanda, R. S. Walia, Manoj Kumar, Ankit D. Oza, Dumitru Doru Burduhos-Nergis and Diana Petronela Burduhos-Nergis

Coatings 2022, 12(10), 1506; https://doi.org/10.3390/coatings12101506 - 9 Oct 2022

Cited by 7 | Viewed by 2068

Abstract

Burnishing is a cold working technique used as a surface enrichment to meet the desired surface properties of the workpiece. It improves the visual properties, dimensional tolerances, fatigue strength, surface roughness, and hardness of the work material by applying appropriate pressure through a [...] Read more.

Burnishing is a cold working technique used as a surface enrichment to meet the desired surface properties of the workpiece. It improves the visual properties, dimensional tolerances, fatigue strength, surface roughness, and hardness of the work material by applying appropriate pressure through a complex ball burnishing tool to cause plastic deformation. In the current work, the mathematical modeling of the burnishing process was carried out to predict surface roughness by considering the process parameters such as contact radius, penetration depth, and elastic rebound. Further, a customized tungsten carbide (W.C.) insert having a hardness of 80 HRC was developed for the burnishing operation. The micro-hardness of the resulting burnished surface improved from 44 to 48 HRC. The surface quality of the tungsten carbide insert improved by up to 17.1 nm through polishing. Several experiments were performed by selecting appropriate process parameters using developed model feedback. The surface quality of the workpiece improved by up to 45 nm, which resulted in automatic improvements in fatigue strength up to seven times that of the virgin material. The results predicted from the mathematical model were in good agreement (less than 5% deviation) with the experimental results. This study helps to understand the surface formation mechanism in the burnishing process in more detail. Additionally, the achieved results show a significant improvement in the surface finish (~95%), indicating the potential of the burnishing process and how fast and cost-effective it is. The novelty of this paper lies in the improvement in surface roughness and the validation of our mathematical model results with the experimental results. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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20 pages, 14561 KiB

Open AccessArticle

Analysis of the Physical-Mechanical Properties of the Zinc Phosphate Layer Deposited on a Nodular Cast Iron Substrate

by Carmen Nejneru, Diana-Petronela Burduhos-Nergis, Mihai Axinte, Manuela Cristina Perju and Costica Bejinariu

Coatings 2022, 12(10), 1384; https://doi.org/10.3390/coatings12101384 - 22 Sep 2022

Cited by 1 | Viewed by 1637

Abstract

The rotors of submersible wastewater pumps, generally made of nodular graphite cast iron, are subjected to complex processes of corrosive erosion during operation. To improve the characteristics of erosion resistance by impact with solid particles in the corrosive environment of wastewater, cast iron [...] Read more.

The rotors of submersible wastewater pumps, generally made of nodular graphite cast iron, are subjected to complex processes of corrosive erosion during operation. To improve the characteristics of erosion resistance by impact with solid particles in the corrosive environment of wastewater, cast iron was subjected to a chemical phosphating treatment. In the paper, the scratch test behaviour of nodular cast iron and phosphate nodular cast iron is analysed comparatively, studying the behaviour of the deposited layer and its adhesion to the substrate. The nanoindentation characteristics of nodular cast iron and phosphate nodular cast iron were also studied. It was observed that the deposited layer is not compact, but when pressed, it does not crack and does not detach from the substrate; it is impregnated in the substrate in the metal matrix, but not on the area with carbon nodules. The SEM micrographs show that the deposited phosphate layer is relatively porous and can change the behaviour of the liquid flow moving on the surface of the rotor due to its hydrophilic behaviour; this also allows the formation of a boundary layer that adheres to the surface of the rotor and protects it from the impacts of microparticles driven by the liquid stream. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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25 pages, 14707 KiB

Open AccessArticle

Corrosion Behaviour of Nodular Cast Iron Used for Rotor Manufacturing in Different Wastewaters

by Carmen Nejneru, Diana-Petronela Burduhos-Nergis, Mihai Axinte, Manuela Cristina Perju and Costica Bejinariu

Coatings 2022, 12(7), 911; https://doi.org/10.3390/coatings12070911 - 28 Jun 2022

Cited by 2 | Viewed by 2048

Abstract

Submersible drainage sump pumps work in a highly corrosive environment, forming films with corrosive reaction products on the surface. Pump rotors are high-demand parts, so they are made of quality materials with good wear and corrosion resistance properties such as nodular graphite cast [...] Read more.

Submersible drainage sump pumps work in a highly corrosive environment, forming films with corrosive reaction products on the surface. Pump rotors are high-demand parts, so they are made of quality materials with good wear and corrosion resistance properties such as nodular graphite cast iron. This paper analyses the corrosion behaviour of cast iron used in the manufacture of rotors in three types of wastewaters, with variable pH. Nodular graphite cast iron samples were immersed in wastewater for 30, 60, and 90 days and tested by linear polarisation and electrochemical impedance spectroscopy (EIS). Also, the layers of reaction products formed on the surface of the material were analysed by SEM and EDS. The results showed that nodular cast-iron immersed in wastewater with acidic pH showed intense corrosion, the oxide layer formed on its surface is unstable. Also, the final structure of the product layer is that of a tri-layer with cations and anions absorbed from the corrosion media: the double-electric layer directly connected to the metal surface, an internal layer consisting of ferrous compounds and ferric compounds that control the diffusion of oxygen, an outer layer, and a compact crust of ferric compounds. The change in the pH of the wastewater has a major influence on the corrosion rate of the cast iron, which increases from 356.4 µm/year in DWW-1 (6.5 pH) to 1440 µm/year in DWW-2 (3 pH) and 1743 µm/year DWWW-3 (11 pH) respectively. As can be seen, the experimental study covers the problem of the corrosion behaviour of the pump rotor in various types of wastewaters this aspect is particularly important for the good use of wastewater pumps and to predict possible deviations for the operation of the equipment within the treatment plants. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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Review

Jump to: Research

25 pages, 4504 KiB

Open AccessReview

Corrosion of Anodized Titanium Alloys

by Jesús Manuel Jáquez-Muñoz, Citlalli Gaona-Tiburcio, Ce Tochtli Mendez-Ramirez, Martha Guadalupe Carrera-Ramirez, Miguel Angel Baltazar-Zamora, Griselda Santiago-Hurtado, Maria Lara-Banda, Francisco Estupiñan-Lopez, Demetrio Nieves-Mendoza and Facundo Almeraya-Calderon

Coatings 2024, 14(7), 809; https://doi.org/10.3390/coatings14070809 - 28 Jun 2024

Viewed by 713

Abstract

Ti and Ti alloys are employed in demanding industries such as aerospace, automotive, biomedical, aeronautic, structural, naval, and chemical, thanks to their resistance to corrosion due to the formation of the TiO₂ film on the surface. Diverse research has established that different [...] Read more.

Ti and Ti alloys are employed in demanding industries such as aerospace, automotive, biomedical, aeronautic, structural, naval, and chemical, thanks to their resistance to corrosion due to the formation of the TiO₂ film on the surface. Diverse research has established that different corrosive media could attack the oxide layer. One way to generate a stable, compact, and continuous oxide film is through anodizing treatment. The efficiency of anodization depends on diverse factors such as the microstructure, chemical composition of alloys, pH of electrolyte, time, and temperature of anodizing. This review aims to examine the corrosion resistance of the anodized layer on Ti and Ti alloys, with different parameters. The discussion is centered on the influence of the different parameters and alloy properties in the effectivity of anodizing when they are characterized by electrochemical techniques while studying the behavior of oxide. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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11 pages, 4299 KiB

Open AccessReview

High-Entropy Alloy for Thin Film Application: A Review

by Nur Izzati Muhammad Nadzri, Dewi Suriyani Che Halin, Mohd Mustafa Al Bakri Abdullah, Sudha Joseph, Mohd Arif Anuar Mohd Salleh, Petrica Vizureanu, Diana-Petronela Burduhos-Nergis and Andrei Victor Sandu

Coatings 2022, 12(12), 1842; https://doi.org/10.3390/coatings12121842 - 28 Nov 2022

Cited by 8 | Viewed by 3797

Abstract

High entropy alloy (HEA) involves the addition of five or more elements into the materials system. This provides a multidimensional configuration space that is limitless in terms of its properties and functions. Some high-entropy alloys have already been shown to have superior properties [...] Read more.

High entropy alloy (HEA) involves the addition of five or more elements into the materials system. This provides a multidimensional configuration space that is limitless in terms of its properties and functions. Some high-entropy alloys have already been shown to have superior properties over conventional alloys, especially the CoCr-based HEA materials. Better high-entropy alloy applications may be discovered, especially in micro- and nano-level structures, hence the development of thin film/coating -based HEA materials. Therefore, in this review paper, we are aiming to provide recent studies on the thin film/coating-based high-entropy alloy on fundamental issues related to methods of preparation, phase formation and mechanical properties. We found that sputtering has been extensively used to grow thin-film-based HEAs as it allowed parameters to be controlled with homogeneous growth. The evolution from bulk to thin samples can also be observed with the mechanical properties has exceeded the bulk-based HEA expectations, which are high hardness, better interfacial bonding and tribological behaviour and higher corrosion resistant. Full article

(This article belongs to the Special Issue Oxidation, Wear, Corrosion Behaviors and Activated Bonding Properties of Coatings Deposited on Metals)

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