Pub Date : 2023-10-06DOI: 10.1177/13506501231197486
Thomas Finch, Tomas Vitu, Tomas Polcar
Aerospace actuation gearboxes operate in low-temperature environments where increased lubricant viscosity leads to significant no-load power losses. Replacing fluid lubricants with coatings applied to the gear teeth is one potential approach to improving gearbox efficiency. Here we develop an approach to determining average wear rates of coated gears using a power-recirculating test stand, profile measurements and a model of the tooth contact. Worn gears are inspected using scanning electron imagery, and energy dispersive X-ray and Raman spectroscopy to understand the wear mechanisms and failure modes. Average coefficients of friction are determined at 20°C and −40°C using a power-absorbing test stand and isolation of tooth friction losses by calculation. These methods are then demonstrated on a promising C/Cr composite coating.
{"title":"Wear and friction of self-lubricating coatings applied to spur gears in fluid- free aerospace actuation gearboxes","authors":"Thomas Finch, Tomas Vitu, Tomas Polcar","doi":"10.1177/13506501231197486","DOIUrl":"https://doi.org/10.1177/13506501231197486","url":null,"abstract":"Aerospace actuation gearboxes operate in low-temperature environments where increased lubricant viscosity leads to significant no-load power losses. Replacing fluid lubricants with coatings applied to the gear teeth is one potential approach to improving gearbox efficiency. Here we develop an approach to determining average wear rates of coated gears using a power-recirculating test stand, profile measurements and a model of the tooth contact. Worn gears are inspected using scanning electron imagery, and energy dispersive X-ray and Raman spectroscopy to understand the wear mechanisms and failure modes. Average coefficients of friction are determined at 20°C and −40°C using a power-absorbing test stand and isolation of tooth friction losses by calculation. These methods are then demonstrated on a promising C/Cr composite coating.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135352477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-06DOI: 10.1177/13506501231204655
B. Bilvatej, J. Naveen, N. Karthikeyan, M. N. F. Norrrahim, Victor Feizal Knight, M. Jawaid, M. T. H. Sultan, Mallikarjuna Reddy Dagalahal, M. Chandrasekar, Tamil Moli Loganathan
The use of asbestos in brake pads is being eliminated due to its carcinogenic effect. Due to this, there is a need for better alternative in the brake pad material to replace asbestos fibers. This leads to the development of more natural fibers/filler-based brake pads which are safer to the environment, cheaper, and readily available. Moreover, bio fillers-based brake pads have shown excellent performance compared to asbestos. This paper addresses the different composition of brake pad materials and manufacturing techniques. Common binders like epoxy resin, Phenolic resin-based brake pads were analyzed and its effect on the mechanical, tribological, and thermal performance were critically analyzed. Also, the performance of metal matrix-based brake pad has been analyzed in detail. It has been observed that utilizing natural fibers as a reinforcement provides an excellent braking performance compared to metallic and carbon fiber-based brake pads. This research will open new avenues towards “Net Zero.”
{"title":"Progress in polymeric and metallic brake pads: A comprehensive review","authors":"B. Bilvatej, J. Naveen, N. Karthikeyan, M. N. F. Norrrahim, Victor Feizal Knight, M. Jawaid, M. T. H. Sultan, Mallikarjuna Reddy Dagalahal, M. Chandrasekar, Tamil Moli Loganathan","doi":"10.1177/13506501231204655","DOIUrl":"https://doi.org/10.1177/13506501231204655","url":null,"abstract":"The use of asbestos in brake pads is being eliminated due to its carcinogenic effect. Due to this, there is a need for better alternative in the brake pad material to replace asbestos fibers. This leads to the development of more natural fibers/filler-based brake pads which are safer to the environment, cheaper, and readily available. Moreover, bio fillers-based brake pads have shown excellent performance compared to asbestos. This paper addresses the different composition of brake pad materials and manufacturing techniques. Common binders like epoxy resin, Phenolic resin-based brake pads were analyzed and its effect on the mechanical, tribological, and thermal performance were critically analyzed. Also, the performance of metal matrix-based brake pad has been analyzed in detail. It has been observed that utilizing natural fibers as a reinforcement provides an excellent braking performance compared to metallic and carbon fiber-based brake pads. This research will open new avenues towards “Net Zero.”","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135346005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-04DOI: 10.1177/13506501231205171
Yakup Artun, C Oktay Azeloglu, Gökhan Taylan
Journal bearings are essential machine elements that are widely used in the bearing of rotating or oscillating machine parts. Many studies in the literature examine the tribological properties of journal bearings. Most of these studies focus on polymer journal bearings and testing the tribological performances of different bearing materials with the same surface quality. In this article, radial journal bearings produced from ultra-high molecular weight polyethylene (UHMWPE) material and polyoxymethylene (POM) material in two different surface qualities in the range of N7–N8 and N10–N11 were tested under different load and different speed scenarios and their tribological performances and relationship of this performance between material and surface roughness were investigated. For this purpose, first of all, bearing samples were designed and manufactured. All samples’ tribological and physical properties before the tests were measured, and then tests were carried out according to the determined scenarios. Different loads, different speeds, and different sliding distances were used in the scenarios. As a result, 96 tests were carried out by testing each situation three times in eight scenarios, with two different surface qualities from two different materials. In the tests, the friction coefficient, temperature, and weight loss values of all samples were measured, and after the tests, surface roughness measurements and SEM analyses were made. As a result, all the data obtained from the tests and measuring devices were compared with the pre-test conditions and material and surface quality. The results obtained from the comparisons and the evaluations of tribological performance are discussed in the conclusion part. The study results show that the material and the surface quality significantly affect the tribological performance.
{"title":"Investigation of the tribological properties of POM and UHMWPE radial journal bearings made with different surface quality","authors":"Yakup Artun, C Oktay Azeloglu, Gökhan Taylan","doi":"10.1177/13506501231205171","DOIUrl":"https://doi.org/10.1177/13506501231205171","url":null,"abstract":"Journal bearings are essential machine elements that are widely used in the bearing of rotating or oscillating machine parts. Many studies in the literature examine the tribological properties of journal bearings. Most of these studies focus on polymer journal bearings and testing the tribological performances of different bearing materials with the same surface quality. In this article, radial journal bearings produced from ultra-high molecular weight polyethylene (UHMWPE) material and polyoxymethylene (POM) material in two different surface qualities in the range of N7–N8 and N10–N11 were tested under different load and different speed scenarios and their tribological performances and relationship of this performance between material and surface roughness were investigated. For this purpose, first of all, bearing samples were designed and manufactured. All samples’ tribological and physical properties before the tests were measured, and then tests were carried out according to the determined scenarios. Different loads, different speeds, and different sliding distances were used in the scenarios. As a result, 96 tests were carried out by testing each situation three times in eight scenarios, with two different surface qualities from two different materials. In the tests, the friction coefficient, temperature, and weight loss values of all samples were measured, and after the tests, surface roughness measurements and SEM analyses were made. As a result, all the data obtained from the tests and measuring devices were compared with the pre-test conditions and material and surface quality. The results obtained from the comparisons and the evaluations of tribological performance are discussed in the conclusion part. The study results show that the material and the surface quality significantly affect the tribological performance.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"128 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135591396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When the hydrostatic thrust bearings operate under conditions of high speed and heavy load, the oil film will be strongly sheared and squeezed, which will increase the temperature of the hydrostatic oil film, resulting in uneven deformation of the workbench and tribology in serious cases. The deformation of the friction pair greatly affects the stability of the workbench during operation, and then affects the machining accuracy. Taking the hydrostatic thrust bearings as the research object, the model of hydrostatic thrust bearings was established based on the fluid–thermosolid coupling theory, and the influencing factors of the deformation of the hydrostatic thrust bearings are analyzed using ANSYS Workbench software, and the influencing laws are discussed. Finally, the correctness of the simulation method is verified by experiments. The results show that the larger the lubricating oil viscosity, the greater the deformation of the guide surface and the oil pad. With the increase in the rotation rate, the deformation of the guide surface and the oil pad increases continuously. With the increase in the inlet flow rate, the deformation of the guide surface and the oil pad is continuously reduced. In engineering practice, on the premise of ensuring the bearings capacity, low-viscosity lubricating oil should be used as much as possible, the rotation rate should be lower, or the inlet flow rate should be increased.
{"title":"Research on influencing factors of deformation of hydrostatic thrust bearings","authors":"Xiao-Dong Yu, Hai-Xin Liu, Fei-Hu Zhao, Rui-Chao Li, Kai-Xuan Sun, Yi-Han Wang, Li-Bo Guan, Rui-Chun Dai, Wen-Tao Jia, Jun-Feng Wang, Hui Jiang, Jian-Hua Jiao","doi":"10.1177/13506501231196436","DOIUrl":"https://doi.org/10.1177/13506501231196436","url":null,"abstract":"When the hydrostatic thrust bearings operate under conditions of high speed and heavy load, the oil film will be strongly sheared and squeezed, which will increase the temperature of the hydrostatic oil film, resulting in uneven deformation of the workbench and tribology in serious cases. The deformation of the friction pair greatly affects the stability of the workbench during operation, and then affects the machining accuracy. Taking the hydrostatic thrust bearings as the research object, the model of hydrostatic thrust bearings was established based on the fluid–thermosolid coupling theory, and the influencing factors of the deformation of the hydrostatic thrust bearings are analyzed using ANSYS Workbench software, and the influencing laws are discussed. Finally, the correctness of the simulation method is verified by experiments. The results show that the larger the lubricating oil viscosity, the greater the deformation of the guide surface and the oil pad. With the increase in the rotation rate, the deformation of the guide surface and the oil pad increases continuously. With the increase in the inlet flow rate, the deformation of the guide surface and the oil pad is continuously reduced. In engineering practice, on the premise of ensuring the bearings capacity, low-viscosity lubricating oil should be used as much as possible, the rotation rate should be lower, or the inlet flow rate should be increased.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135690005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The low service performance and sudden failure characteristics of coated self-lubricating spherical plain bearings (SPBs) limit their engineering application prospects. In the current study, two new self-lubricating coatings types were applied to the bearing contact surfaces. The bearings were compared and investigated using life tests. Furthermore, the wear failure mechanism was investigated. The results show that self-lubricating coatings improved the service performance of the traditional bearings with manganese phosphate coating. Among them, double-sided coated bearings had the best service performance and life. More interestingly, the torque and temperature rise signal curves will show a notable signal downstage before the signal mutation stage. The large-area and complete mixed friction transfer film on the contact surfaces was the main reason for the signal downstage. Moreover, the failure mechanism changed from abrasive wear to adhesive wear and fatigue wear with the increment of load. This study results preliminarily verify the performance improvement of high-performance coatings and provide a theoretical reference for further breaking through the engineering application bottleneck of coated self-lubricating SPBs.
{"title":"A new coated self-lubricating spherical plain bearing with high performance and excellent security","authors":"Yunfan Liu, Guozheng Ma, Lina Zhu, Cuihong Han, Zhen Li, Bin Zhang, Haichao Zhao, Haidou Wang, Shuying Chen","doi":"10.1177/13506501231203034","DOIUrl":"https://doi.org/10.1177/13506501231203034","url":null,"abstract":"The low service performance and sudden failure characteristics of coated self-lubricating spherical plain bearings (SPBs) limit their engineering application prospects. In the current study, two new self-lubricating coatings types were applied to the bearing contact surfaces. The bearings were compared and investigated using life tests. Furthermore, the wear failure mechanism was investigated. The results show that self-lubricating coatings improved the service performance of the traditional bearings with manganese phosphate coating. Among them, double-sided coated bearings had the best service performance and life. More interestingly, the torque and temperature rise signal curves will show a notable signal downstage before the signal mutation stage. The large-area and complete mixed friction transfer film on the contact surfaces was the main reason for the signal downstage. Moreover, the failure mechanism changed from abrasive wear to adhesive wear and fatigue wear with the increment of load. This study results preliminarily verify the performance improvement of high-performance coatings and provide a theoretical reference for further breaking through the engineering application bottleneck of coated self-lubricating SPBs.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135536767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-27DOI: 10.1177/13506501231203032
Huiyi Yang, Yang Xu, Chao Xu
Due to inherent nonlinear stiffness and damping characteristics, dry friction interfaces have a significant impact on the dynamics of jointed structures. When two surfaces are brought into purely normal contact, contact pressure distribution is of high concern. This work focused on the statistics of the contact pressure distribution between a rough surface and a smooth rigid plane, which provides new insight into the interface contact behaviour. First, the fractal rough surface is generated using the Weierstrass–Mandelbrot function with measured roughness parameters. With meshed rough surfaces, an elastic–plastic finite element contact analysis is performed to determine the contact pressure distribution. Then, the results of contact pressure are statistically analysed. The effects of roughness and contact load on contact area, contact stiffness and mean contact pressure are thoroughly investigated. The probability distribution of contact pressure is determined by fitting a continuous function using a twofold Weibull mixture model. The proposed probability distribution function is found to be capable of describing contact pressure. The contact pressure distribution is affected by the surface fractal characteristics and evolves with the contact load.
{"title":"A statistics view of contact pressure distribution for normal contact of fractal surfaces","authors":"Huiyi Yang, Yang Xu, Chao Xu","doi":"10.1177/13506501231203032","DOIUrl":"https://doi.org/10.1177/13506501231203032","url":null,"abstract":"Due to inherent nonlinear stiffness and damping characteristics, dry friction interfaces have a significant impact on the dynamics of jointed structures. When two surfaces are brought into purely normal contact, contact pressure distribution is of high concern. This work focused on the statistics of the contact pressure distribution between a rough surface and a smooth rigid plane, which provides new insight into the interface contact behaviour. First, the fractal rough surface is generated using the Weierstrass–Mandelbrot function with measured roughness parameters. With meshed rough surfaces, an elastic–plastic finite element contact analysis is performed to determine the contact pressure distribution. Then, the results of contact pressure are statistically analysed. The effects of roughness and contact load on contact area, contact stiffness and mean contact pressure are thoroughly investigated. The probability distribution of contact pressure is determined by fitting a continuous function using a twofold Weibull mixture model. The proposed probability distribution function is found to be capable of describing contact pressure. The contact pressure distribution is affected by the surface fractal characteristics and evolves with the contact load.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135537322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-20DOI: 10.1177/13506501231201894
Siwei Dai, Jianchun Fan, Siqi Yang
When studying the erosion behavior of fracturing pipelines, it is inevitable to consider the exacerbating effect of fluctuating internal pressure on pipeline erosion damage. Therefore, an erosion experimental apparatus capable of applying fluctuating tensile loads to specimens was developed to investigate the erosion rate of 35CrMo steel at different average tensile stresses (0–500 MPa), impact angles (15–90°), flow velocity (7.5–20 m/s), and experimental times (10–60 min), and to analyze the erosion damage mechanism under fluctuating loads by observing the microstructure within the erosion scars using scanning electron microscope. The results indicated that erosion rate increased up to 36.84% compared to that without loading under the same erosion condition. Erosion rate increased up to 822.00% when velocity increased from minimum to maximum. Under fluctuating loads, the deepest part of the erosion scar cracked first and the specimen eventually fractured completely along with its entire width, demonstrating that the newly established experimental conditions can well reproduce the sudden bursting phenomenon common to high-pressure pipelines that erode under harsh conditions. The fracture of the specimen shows laminar structure, which is a typical damage feature resulting from the combined effect of a great number of tensile stress cycles and erosion wear.
{"title":"Experimental study of erosion behavior under fluctuating tensile loads","authors":"Siwei Dai, Jianchun Fan, Siqi Yang","doi":"10.1177/13506501231201894","DOIUrl":"https://doi.org/10.1177/13506501231201894","url":null,"abstract":"When studying the erosion behavior of fracturing pipelines, it is inevitable to consider the exacerbating effect of fluctuating internal pressure on pipeline erosion damage. Therefore, an erosion experimental apparatus capable of applying fluctuating tensile loads to specimens was developed to investigate the erosion rate of 35CrMo steel at different average tensile stresses (0–500 MPa), impact angles (15–90°), flow velocity (7.5–20 m/s), and experimental times (10–60 min), and to analyze the erosion damage mechanism under fluctuating loads by observing the microstructure within the erosion scars using scanning electron microscope. The results indicated that erosion rate increased up to 36.84% compared to that without loading under the same erosion condition. Erosion rate increased up to 822.00% when velocity increased from minimum to maximum. Under fluctuating loads, the deepest part of the erosion scar cracked first and the specimen eventually fractured completely along with its entire width, demonstrating that the newly established experimental conditions can well reproduce the sudden bursting phenomenon common to high-pressure pipelines that erode under harsh conditions. The fracture of the specimen shows laminar structure, which is a typical damage feature resulting from the combined effect of a great number of tensile stress cycles and erosion wear.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136313560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-16DOI: 10.1177/13506501231201692
Xin Pei, Wanyou Yang
A new contact model of finite-length crowned roller bearing, capable of handling lubrication, eccentric load, and misalignment situations, is established in this study. Simulation results of interface pressure, film thickness distribution, flash temperature, and subsurface stress can be obtained with different speeds, misalignment angles, load eccentricity, and roller trimming parameters. It is found that edge trimming can greatly reduce the stress concentration at the edge, and there are optimal trimming parameters to minimize the concentrated stress under normal load and eccentric load. When the eccentric load exceeds a certain angle, the increase in the maximum stress can be very large, which may lead to premature failure of the interface. Meanwhile, the staggering velocity caused by the misalignment of the roller axis also has a certain influence on the distribution of the lubricating film.
{"title":"Investigation of the misalignment and modification for crown roller contacts under mixed lubrication","authors":"Xin Pei, Wanyou Yang","doi":"10.1177/13506501231201692","DOIUrl":"https://doi.org/10.1177/13506501231201692","url":null,"abstract":"A new contact model of finite-length crowned roller bearing, capable of handling lubrication, eccentric load, and misalignment situations, is established in this study. Simulation results of interface pressure, film thickness distribution, flash temperature, and subsurface stress can be obtained with different speeds, misalignment angles, load eccentricity, and roller trimming parameters. It is found that edge trimming can greatly reduce the stress concentration at the edge, and there are optimal trimming parameters to minimize the concentrated stress under normal load and eccentric load. When the eccentric load exceeds a certain angle, the increase in the maximum stress can be very large, which may lead to premature failure of the interface. Meanwhile, the staggering velocity caused by the misalignment of the roller axis also has a certain influence on the distribution of the lubricating film.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"354 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135308619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-16DOI: 10.1177/13506501231201693
Ravi Prakash Sharma, Mukesh Kumar, Ashiwani Kumar
This research work investigates the physical, mechanical, thermal, thermo-mechanical, and dry sliding wear characteristics of hybrid flyash particulates (F-class; 0 – 20 wt.% at the step of 5%)–basalt fibres (chopped; fixed 10 wt.%) reinforced polyamide 66 polymer composites fabricated using the twin screw extruder and injection moulding machine. Taguchi's design of experiment optimization approach is used for parameter optimization of the dry sliding wear process, followed by analysis of variance analysis. Further, the hybrid AHP-R method is used for ranking optimization based on the performance metrics. It is observed that the composition having 15 wt.% flyash particulates optimizes overall performance metrics, hence recommended for industrial parts fabrications. It has an experimental density of 1.23 g/cc, voids content of 5.93%, water absorption of 4.21%, tensile strength of 110.73 MPa, flexural strength of 146.72 MPa, Rockwell hardness of 62.44 HRM, fracture toughness of 4.17 MPa√m, impact strength of 2.06 J, the thermal conductivity of 1.24 W/mK, and specific wear rate of 7.55 × 10 −4 mm 3 /Nm. The overall subjective ranking of the hybrid polymer composites attunes with the objective ranking by the hybrid AHP-R method.
{"title":"Ranking analysis of flyash – basalt fibre – polyamide 66 polymer composites based on the mechanical and sliding wear performance metrics using hybrid AHP-R method","authors":"Ravi Prakash Sharma, Mukesh Kumar, Ashiwani Kumar","doi":"10.1177/13506501231201693","DOIUrl":"https://doi.org/10.1177/13506501231201693","url":null,"abstract":"This research work investigates the physical, mechanical, thermal, thermo-mechanical, and dry sliding wear characteristics of hybrid flyash particulates (F-class; 0 – 20 wt.% at the step of 5%)–basalt fibres (chopped; fixed 10 wt.%) reinforced polyamide 66 polymer composites fabricated using the twin screw extruder and injection moulding machine. Taguchi's design of experiment optimization approach is used for parameter optimization of the dry sliding wear process, followed by analysis of variance analysis. Further, the hybrid AHP-R method is used for ranking optimization based on the performance metrics. It is observed that the composition having 15 wt.% flyash particulates optimizes overall performance metrics, hence recommended for industrial parts fabrications. It has an experimental density of 1.23 g/cc, voids content of 5.93%, water absorption of 4.21%, tensile strength of 110.73 MPa, flexural strength of 146.72 MPa, Rockwell hardness of 62.44 HRM, fracture toughness of 4.17 MPa√m, impact strength of 2.06 J, the thermal conductivity of 1.24 W/mK, and specific wear rate of 7.55 × 10 −4 mm 3 /Nm. The overall subjective ranking of the hybrid polymer composites attunes with the objective ranking by the hybrid AHP-R method.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135308621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study applied a MoS 2 coating layer on the surface of 100Cr6 bearing steel balls through high-temperature sintering and tested and evaluated the modified friction pair. Compared to the unmodified friction pair, the MoS 2 coating treatment significantly improved the self-lubricating property of the friction pair, reduced the friction coefficient of the friction pair by 0.05, maximum wear depth was reduced by 32% during the test cycle and prolonged the retention time of the PTFE transfer film at the friction interface. After modification, the wear mechanism of the friction pair changed from abrasive wear to fatigue wear and then to slight adhesive wear. Results indicate that MoS 2 coating has great application prospects in improving the tribological properties and operational reliability of spherical plain bearings.
{"title":"Influence of MoS<sub>2</sub> coating treatment on the damage behaviour of the self-lubricating friction pair of spherical plain bearings","authors":"Fatao Zong, Xiaoqiang Yang, Deqiang Tan, Qiang Ye, Yue Hu, Qiang He, Wenfeng Yang, Huiying Gao","doi":"10.1177/13506501231201689","DOIUrl":"https://doi.org/10.1177/13506501231201689","url":null,"abstract":"This study applied a MoS 2 coating layer on the surface of 100Cr6 bearing steel balls through high-temperature sintering and tested and evaluated the modified friction pair. Compared to the unmodified friction pair, the MoS 2 coating treatment significantly improved the self-lubricating property of the friction pair, reduced the friction coefficient of the friction pair by 0.05, maximum wear depth was reduced by 32% during the test cycle and prolonged the retention time of the PTFE transfer film at the friction interface. After modification, the wear mechanism of the friction pair changed from abrasive wear to fatigue wear and then to slight adhesive wear. Results indicate that MoS 2 coating has great application prospects in improving the tribological properties and operational reliability of spherical plain bearings.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135740766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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