Pub Date : 2024-12-20DOI: 10.1016/j.wear.2024.205717
Ali Shabestari Shirazi, Hossein Ali Pakravan
Pneumatic conveying systems, while offering design flexibility through fittings and bends, are susceptible to erosion within these components, compromising system integrity. This study focuses on erosion prediction and mitigation within blinded T-bends using numerical simulations. An Eulerian-Eulerian approach was adopted to model the gas-solid two-phase flow, with an erosion model based on monolayer energy dissipation employed to quantify erosion rates. Numerical results were validated through experimental data. A parametric study was conducted to investigate the influence of air mass flow rate (0.025–0.07 kg/s), particle mass flow rate (1–3 kg/s), and blind end length (L/D = 0.5, 1, 1.5) on erosion. Results indicate a positive correlation between erosion rate and both air and particle mass flow rates, emphasizing the need for optimized airflow conditions. Conversely, increasing the blind end length was found to reduce erosion. This research provides valuable insights for designing pneumatic conveying systems with enhanced durability and efficiency.
{"title":"Numerical Eulerian modeling of erosion in blinded T-Bends: A parametric study","authors":"Ali Shabestari Shirazi, Hossein Ali Pakravan","doi":"10.1016/j.wear.2024.205717","DOIUrl":"10.1016/j.wear.2024.205717","url":null,"abstract":"<div><div>Pneumatic conveying systems, while offering design flexibility through fittings and bends, are susceptible to erosion within these components, compromising system integrity. This study focuses on erosion prediction and mitigation within blinded T-bends using numerical simulations. An Eulerian-Eulerian approach was adopted to model the gas-solid two-phase flow, with an erosion model based on monolayer energy dissipation employed to quantify erosion rates. Numerical results were validated through experimental data. A parametric study was conducted to investigate the influence of air mass flow rate (0.025–0.07 kg/s), particle mass flow rate (1–3 kg/s), and blind end length (L/D = 0.5, 1, 1.5) on erosion. Results indicate a positive correlation between erosion rate and both air and particle mass flow rates, emphasizing the need for optimized airflow conditions. Conversely, increasing the blind end length was found to reduce erosion. This research provides valuable insights for designing pneumatic conveying systems with enhanced durability and efficiency.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"564 ","pages":"Article 205717"},"PeriodicalIF":5.3,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-12-20DOI: 10.1016/j.wear.2024.205718
Nilesh V. Dorkar , Young-Wook Kim , B. Venkata Manoj Kumar
Hot-pressed SiC-in situ Zr2CN composites were subjected to sliding against SiC counterbody in varying conditions of humidity (≤20 % RH and ≥90 % RH), and temperature (25 °C and 500 °C). Results demonstrated that sliding friction and wear decreased with increasing ZrN content from 0 to 10 vol% in the initial powder composition. Wear resistance increased by 37% at dry, 79% at humid and 54% at high temperature condition for the composite with 10 vol% initial ZrN content in comparison to monolithic SiC ceramics. While the presence of Zr2CN phase in SiC ceramics reduced fracture and pull-out, friction and wear are found to be minimum at humid condition due to the formation of thick tribo-oxidative layer at the contact. Results obtained from this study indicate the potential aspects of SiC-10 vol% ZrN composites in tribological applications where material in sliding contacts experiences extreme conditions of humidity and temperature.
{"title":"Friction and wear mechanisms of hot-pressed SiC-in situ Zr2CN composites in extreme conditions of humidity and temperature","authors":"Nilesh V. Dorkar , Young-Wook Kim , B. Venkata Manoj Kumar","doi":"10.1016/j.wear.2024.205718","DOIUrl":"10.1016/j.wear.2024.205718","url":null,"abstract":"<div><div>Hot-pressed SiC-<em>in situ</em> Zr<sub>2</sub>CN composites were subjected to sliding against SiC counterbody in varying conditions of humidity (≤20 % RH and ≥90 % RH), and temperature (25 °C and 500 °C). Results demonstrated that sliding friction and wear decreased with increasing ZrN content from 0 to 10 vol% in the initial powder composition. Wear resistance increased by 37% at dry, 79% at humid and 54% at high temperature condition for the composite with 10 vol% initial ZrN content in comparison to monolithic SiC ceramics. While the presence of Zr<sub>2</sub>CN phase in SiC ceramics reduced fracture and pull-out, friction and wear are found to be minimum at humid condition due to the formation of thick tribo-oxidative layer at the contact. Results obtained from this study indicate the potential aspects of SiC-10 vol% ZrN composites in tribological applications where material in sliding contacts experiences extreme conditions of humidity and temperature.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"564 ","pages":"Article 205718"},"PeriodicalIF":5.3,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143096712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-12-20DOI: 10.1016/j.wear.2024.205716
Chengtong Ye , Lina Jia , Yan Qi , Zuheng Jin , Yanyu Liu , Wenbo Wang , Hu Zhang
The effects of Mg on wear resistance of SiCp/Al-Si-Mg composites were studied. Comparative analyses between equivalent von-Mises stresses and yield stresses of α-Al and SiC were calculated, and quasi-in-situ observation were conducted to reveal the wear behavior and modes. During reciprocating frictions, the matrix with better plasticity is the weak part in composites. Due to the deformation discontinuity, the interface between SiC and matrix tends to separate leading to surface cracks and wear failure. Therefore, increasing the strength of α-Al and improving the deformation coordination between α-Al and SiC are the crux to improve wear resistance. 1 wt% Mg addition introduces Mg-Si GP zones and B′ precipitates into α-Al, resulting in precipitation strengthening which improves the wear resistance of composites.
{"title":"Strengthening effects of Mg-Si precipitates on wear resistance of SiCp/Al-Si-Mg composites","authors":"Chengtong Ye , Lina Jia , Yan Qi , Zuheng Jin , Yanyu Liu , Wenbo Wang , Hu Zhang","doi":"10.1016/j.wear.2024.205716","DOIUrl":"10.1016/j.wear.2024.205716","url":null,"abstract":"<div><div>The effects of Mg on wear resistance of SiC<sub>p</sub>/Al-Si-Mg composites were studied. Comparative analyses between equivalent von-Mises stresses and yield stresses of α-Al and SiC were calculated, and quasi-in-situ observation were conducted to reveal the wear behavior and modes. During reciprocating frictions, the matrix with better plasticity is the weak part in composites. Due to the deformation discontinuity, the interface between SiC and matrix tends to separate leading to surface cracks and wear failure. Therefore, increasing the strength of α-Al and improving the deformation coordination between α-Al and SiC are the crux to improve wear resistance. 1 wt% Mg addition introduces Mg-Si GP zones and B′ precipitates into α-Al, resulting in precipitation strengthening which improves the wear resistance of composites.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"564 ","pages":"Article 205716"},"PeriodicalIF":5.3,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-12-19DOI: 10.1016/j.wear.2024.205711
R.C. Rocha , H. Ewald , E.M. Almeida , A.B. Rezende , P.R. Mei
The tribological behavior of rails and wheels is a topic of great relevance to the railway industry. However, simulating the complex interactions that occur in the wheel-rail contact presents a challenge to researchers. In this context, tests using the twin-disc tribometer have emerged as a promising alternative. In the test, it is common for the disc with the higher speed (driving disc) to be used to simulate the behavior of the wheel, while the disc with the lower speed (driven disc) simulates the rail. Nonetheless, many studies base their discussions on the differences in tribological behavior between the wheel and the rail considering only microstructural aspects and the hardness relationship between the materials of the wheel and the rail. This study evaluated the effect of slip rates of 1 %, 3 %, and 5 %, as well as the residual stresses generated, on the tribological behavior of class C wheel steel. To isolate the effects of microstructure and hardness, the same material was used in the fabrication of both discs employed in the tests. The results showed that although both discs were made of the same material, the driving disc exhibited greater wear than the driven disc. This finding is frequently reported in the literature, mainly due to the microstructural differences between the discs; still, this study, which used the same material for both discs, achieved the same result. This highlights the need for further discussion on the causes of wear on the driving disc, as the wear may not be solely attributed to the microstructural effects of the materials, contrarily to what is widely indicated in the literature. The results of this study demonstrate that the different residual stresses on the discs, along with the contact dynamics, play a significant role influencing the tribological behavior of the materials tested in the twin-disc tribometer.
{"title":"Effect of slip on the residual stress and tribological behavior of a class C wheel steel after twin-disc tests","authors":"R.C. Rocha , H. Ewald , E.M. Almeida , A.B. Rezende , P.R. Mei","doi":"10.1016/j.wear.2024.205711","DOIUrl":"10.1016/j.wear.2024.205711","url":null,"abstract":"<div><div>The tribological behavior of rails and wheels is a topic of great relevance to the railway industry. However, simulating the complex interactions that occur in the wheel-rail contact presents a challenge to researchers. In this context, tests using the twin-disc tribometer have emerged as a promising alternative. In the test, it is common for the disc with the higher speed (driving disc) to be used to simulate the behavior of the wheel, while the disc with the lower speed (driven disc) simulates the rail. Nonetheless, many studies base their discussions on the differences in tribological behavior between the wheel and the rail considering only microstructural aspects and the hardness relationship between the materials of the wheel and the rail. This study evaluated the effect of slip rates of 1 %, 3 %, and 5 %, as well as the residual stresses generated, on the tribological behavior of class C wheel steel. To isolate the effects of microstructure and hardness, the same material was used in the fabrication of both discs employed in the tests. The results showed that although both discs were made of the same material, the driving disc exhibited greater wear than the driven disc. This finding is frequently reported in the literature, mainly due to the microstructural differences between the discs; still, this study, which used the same material for both discs, achieved the same result. This highlights the need for further discussion on the causes of wear on the driving disc, as the wear may not be solely attributed to the microstructural effects of the materials, contrarily to what is widely indicated in the literature. The results of this study demonstrate that the different residual stresses on the discs, along with the contact dynamics, play a significant role influencing the tribological behavior of the materials tested in the twin-disc tribometer.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"564 ","pages":"Article 205711"},"PeriodicalIF":5.3,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-12-19DOI: 10.1016/j.wear.2024.205715
Xuhu Zhang , Jiqiang Ma , Jie Guo , Juanjuan Chen , Hui Tan , Jun Cheng , Shengyu Zhu , Jun Yang
Current-carrying friction and wear issues have a significant impact on the performance and service life of electrical systems. This paper investigated lubricating behavior of gallium-based liquid metal (GLM) for the Cu/Al current-carrying tribo-pair. The results showed that when there is GLM lubrication, the coefficient of friction is in the range of 0.19–0.27, and the wear rate of Cu alloy is in the range of 0.87 × 10⁻⁵ mm³/Nm to 1.83 × 10⁻⁵ mm³/Nm. Compared without GLM lubricant, the coefficient of friction is decreased by approximately 1.3–2.5 times, and the wear rate is decreased by around 3.1 to 8.3 times. Its main lubrication mechanism is to generate a uniform and stable Ga-Al metal film at the friction interface, thereby effectively preventing the direct contact between the tribo-pairs and the occurrence of arc ablation.
{"title":"Current-carrying lubricating behavior of gallium-based liquid metal for Cu/Al tribo-pair","authors":"Xuhu Zhang , Jiqiang Ma , Jie Guo , Juanjuan Chen , Hui Tan , Jun Cheng , Shengyu Zhu , Jun Yang","doi":"10.1016/j.wear.2024.205715","DOIUrl":"10.1016/j.wear.2024.205715","url":null,"abstract":"<div><div>Current-carrying friction and wear issues have a significant impact on the performance and service life of electrical systems. This paper investigated lubricating behavior of gallium-based liquid metal (GLM) for the Cu/Al current-carrying tribo-pair. The results showed that when there is GLM lubrication, the coefficient of friction is in the range of 0.19–0.27, and the wear rate of Cu alloy is in the range of 0.87 × 10⁻⁵ mm³/Nm to 1.83 × 10⁻⁵ mm³/Nm. Compared without GLM lubricant, the coefficient of friction is decreased by approximately 1.3–2.5 times, and the wear rate is decreased by around 3.1 to 8.3 times. Its main lubrication mechanism is to generate a uniform and stable Ga-Al metal film at the friction interface, thereby effectively preventing the direct contact between the tribo-pairs and the occurrence of arc ablation.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"564 ","pages":"Article 205715"},"PeriodicalIF":5.3,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143092076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-12-18DOI: 10.1016/j.wear.2024.205714
Ziye Ma , Hainian Wang , Yandi Zhang , Denis Jelagin , Bing Hui
Asphalt pavements constitute an important part of global transportation infrastructure, and their surface texture directly impact driving safety and comfort. Understanding the evolution of surface texture during wear and its effect on friction degradation is essential for pavement maintenance and safety assessment. This study conducted accelerated wear tests on three typical asphalt pavements (AC-13, SMA-13, and OGFC-13) using a self-developed indoor plate accelerated load wear tester (PALWT). A 3D laser scanner and a dynamic friction tester were used for pavement surface modeling and friction measurement. Based on the ISO 25178-2 standard, areal field parameters and functional volume parameters were innovatively introduced into the pavement wear quantification system to reveal the wear mechanisms of material loss and transfer. Results showed that the macrotexture characteristics of the pavement shifted from rough to flat after wear, with peak features gradually disappearing and texture directionality transitioning from multi-directional to the traffic direction. Wear caused a decrease in material at the surface peaks and valley areas while accumulating material in the core area. The dynamic friction coefficient (DFT40, DFT60, and DFT80) of asphalt pavements initially increased (peaking at around 3000 wear cycles) before decreasing and eventually stabilizing. Open-graded and gap-graded pavements generally outperform dense-graded pavements in terms of friction retention. Peak material volume (Vmp) and valley void volume (Vvv) effectively reflected material redistribution during wear across peak, core to valley, showing a strong correlation with skid resistance. Mean peak curvature (Spc) significantly improves skid resistance at low to medium speeds, while texture aspect ratio (Str) becomes critical under high-speed conditions by ensuring stable multidirectional tire-road interaction.
{"title":"Study of the surface texture evolution and friction degradation in asphalt pavements during wear process","authors":"Ziye Ma , Hainian Wang , Yandi Zhang , Denis Jelagin , Bing Hui","doi":"10.1016/j.wear.2024.205714","DOIUrl":"10.1016/j.wear.2024.205714","url":null,"abstract":"<div><div>Asphalt pavements constitute an important part of global transportation infrastructure, and their surface texture directly impact driving safety and comfort. Understanding the evolution of surface texture during wear and its effect on friction degradation is essential for pavement maintenance and safety assessment. This study conducted accelerated wear tests on three typical asphalt pavements (AC-13, SMA-13, and OGFC-13) using a self-developed indoor plate accelerated load wear tester (PALWT). A 3D laser scanner and a dynamic friction tester were used for pavement surface modeling and friction measurement. Based on the ISO 25178-2 standard, areal field parameters and functional volume parameters were innovatively introduced into the pavement wear quantification system to reveal the wear mechanisms of material loss and transfer. Results showed that the macrotexture characteristics of the pavement shifted from rough to flat after wear, with peak features gradually disappearing and texture directionality transitioning from multi-directional to the traffic direction. Wear caused a decrease in material at the surface peaks and valley areas while accumulating material in the core area. The dynamic friction coefficient (DFT40, DFT60, and DFT80) of asphalt pavements initially increased (peaking at around 3000 wear cycles) before decreasing and eventually stabilizing. Open-graded and gap-graded pavements generally outperform dense-graded pavements in terms of friction retention. Peak material volume (Vmp) and valley void volume (Vvv) effectively reflected material redistribution during wear across peak, core to valley, showing a strong correlation with skid resistance. Mean peak curvature (Spc) significantly improves skid resistance at low to medium speeds, while texture aspect ratio (Str) becomes critical under high-speed conditions by ensuring stable multidirectional tire-road interaction.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"564 ","pages":"Article 205714"},"PeriodicalIF":5.3,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143092075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-12-17DOI: 10.1016/j.wear.2024.205712
De-Long Huang , Jin-Kun Xiao , Chen Wang , Zhen-Zhong Zhang , Juan Chen , Ai-Kun Li , Chao Zhang
Sliding electrical contacts play a crucial role in many electrical and mechanical devices, allowing for a stable electrical connection between two relatively moving surfaces. The design and material selection for sliding electrical contacts are vital for ensuring the reliability and performance of the equipment. The AgNi-CNTs composites are prepared by powder metallurgy and hot extrusion. The influences of CNTs content and electric currents on their tribological properties are investigated. The results show that the hardness of the composites increases with the addition of CNTs, which is attributed to the dispersion strengthening by the CNTs and the grain refinement strengthening by the smaller Ni particles. The friction coefficient and wear rate of the AgNi-CNTs composites significantly decrease with an increase in the CNTs content, indicating that CNTs can effectively serve as a lubricant and improve wear resistance. The wear rate of the composites is much higher at 1 A than at 0.1 A, which is due to the arcs generated when current flows through the contact interface, showing a combination of electrical and mechanical wear. The lubricating effect of CNTs facilitates the formation of a uniform transfer layer on the CuBe sheet. High current promotes the formation of a thicker transfer layer, which is due to the softening of the AgNi-CNTs composites caused by Joule heating.
{"title":"Tribological property of AgNi-CNTs composites under electric current","authors":"De-Long Huang , Jin-Kun Xiao , Chen Wang , Zhen-Zhong Zhang , Juan Chen , Ai-Kun Li , Chao Zhang","doi":"10.1016/j.wear.2024.205712","DOIUrl":"10.1016/j.wear.2024.205712","url":null,"abstract":"<div><div>Sliding electrical contacts play a crucial role in many electrical and mechanical devices, allowing for a stable electrical connection between two relatively moving surfaces. The design and material selection for sliding electrical contacts are vital for ensuring the reliability and performance of the equipment. The AgNi-CNTs composites are prepared by powder metallurgy and hot extrusion. The influences of CNTs content and electric currents on their tribological properties are investigated. The results show that the hardness of the composites increases with the addition of CNTs, which is attributed to the dispersion strengthening by the CNTs and the grain refinement strengthening by the smaller Ni particles. The friction coefficient and wear rate of the AgNi-CNTs composites significantly decrease with an increase in the CNTs content, indicating that CNTs can effectively serve as a lubricant and improve wear resistance. The wear rate of the composites is much higher at 1 A than at 0.1 A, which is due to the arcs generated when current flows through the contact interface, showing a combination of electrical and mechanical wear. The lubricating effect of CNTs facilitates the formation of a uniform transfer layer on the CuBe sheet. High current promotes the formation of a thicker transfer layer, which is due to the softening of the AgNi-CNTs composites caused by Joule heating.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"564 ","pages":"Article 205712"},"PeriodicalIF":5.3,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The dry sliding wear behavior of directed energy deposited (DED) 316L stainless steel and its TiB2-ceramic reinforced composite (CRC) is investigated using a pin-on-disc tribometer and compared against wrought 316L alloy. The experimental results show that DED 316L exhibits the lowest wear rate among the three samples, followed by DED 316L + TiB2 composite and the wrought 316L alloy. The morphologies of the worn-out surfaces indicate severe wear (characterized by deeper and wider abrasive groves) in wrought 316L, while mild wear in the case of DED 316L. A thorough examination of the subsurface deformation zones using a scanning electron microscope and electron-back scattered diffraction shows severe distortion of cells just underneath the wear surface and excessive rotation of the grains. Further, the nanoindentation experiments in the subsurface deformation zones reveal softening in the deformed layers of wrought 316L and DED 316L + TiB2 samples. The cellular sub-grain morphology inherent to the DED 316L samples is found to be beneficial for wear resistance as opposed to the TiB2 enriched cell boundaries of the DED 316L + TiB2 composite. The results are discussed with reference to the microstructure, texture and prevalent wear mechanisms among the samples.
{"title":"Tribological behavior of directed energy-deposited 316L stainless steel and its ceramic reinforced composite under dry sliding conditions","authors":"Sourav Kumar , Shubham Chandra , Upadrasta Ramamurty , K. Eswar Prasad","doi":"10.1016/j.wear.2024.205710","DOIUrl":"10.1016/j.wear.2024.205710","url":null,"abstract":"<div><div>The dry sliding wear behavior of directed energy deposited (DED) 316L stainless steel and its TiB<sub>2</sub>-ceramic reinforced composite (CRC) is investigated using a pin-on-disc tribometer and compared against wrought 316L alloy. The experimental results show that DED 316L exhibits the lowest wear rate among the three samples, followed by DED 316L + TiB<sub>2</sub> composite and the wrought 316L alloy. The morphologies of the worn-out surfaces indicate severe wear (characterized by deeper and wider abrasive groves) in wrought 316L, while mild wear in the case of DED 316L. A thorough examination of the subsurface deformation zones using a scanning electron microscope and electron-back scattered diffraction shows severe distortion of cells just underneath the wear surface and excessive rotation of the grains. Further, the nanoindentation experiments in the subsurface deformation zones reveal softening in the deformed layers of wrought 316L and DED 316L + TiB<sub>2</sub> samples. The cellular sub-grain morphology inherent to the DED 316L samples is found to be beneficial for wear resistance as opposed to the TiB<sub>2</sub> enriched cell boundaries of the DED 316L + TiB<sub>2</sub> composite. The results are discussed with reference to the microstructure, texture and prevalent wear mechanisms among the samples.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"564 ","pages":"Article 205710"},"PeriodicalIF":5.3,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-12-15DOI: 10.1016/j.wear.2024.205706
T.-C. Huang , C.-Y. Lin , K.-C. Liao
Tribological experiments were conducted by using a plate-on-disc tribometer to determine the wear rate of polytetrafluoroethylene (PTFE) filled with 5 % glass fiber and 5 % MoS2 sliding against SKD11 counterparts. An experimental approach is proposed to accelerate the wear of PTFE rotary lip seals leading to earlier leakage failure. Numerical simulations based on the wear model with the consideration of the fracture of PTFE composite caused by asperity interactions are introduced to describe the dependency of roughness parameters of both the seal lip and shaft on the dry wear rate. The elasto-hydrodynamic analysis (EHA) integrated with the convolutional neural networks (CNN) model in the U-net architecture is implemented into sealing performance assessments to significantly enhance its computational efficiency. Simulation results show that the predicted minimum sealed pressure required to induce the leakage failure of seals are in fair agreement with the corresponding experimental measurements.
{"title":"Numerical sealing performance assessments of PTFE rotary lip seals based on the elasto-hydrodynamic analysis with the consideration of asperity interactions and accelerated wear experimental validations","authors":"T.-C. Huang , C.-Y. Lin , K.-C. Liao","doi":"10.1016/j.wear.2024.205706","DOIUrl":"10.1016/j.wear.2024.205706","url":null,"abstract":"<div><div>Tribological experiments were conducted by using a plate-on-disc tribometer to determine the wear rate of polytetrafluoroethylene (PTFE) filled with 5 % glass fiber and 5 % MoS<sub>2</sub> sliding against SKD11 counterparts. An experimental approach is proposed to accelerate the wear of PTFE rotary lip seals leading to earlier leakage failure. Numerical simulations based on the wear model with the consideration of the fracture of PTFE composite caused by asperity interactions are introduced to describe the dependency of roughness parameters of both the seal lip and shaft on the dry wear rate. The elasto-hydrodynamic analysis (EHA) integrated with the convolutional neural networks (CNN) model in the U-net architecture is implemented into sealing performance assessments to significantly enhance its computational efficiency. Simulation results show that the predicted minimum sealed pressure required to induce the leakage failure of seals are in fair agreement with the corresponding experimental measurements.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"564 ","pages":"Article 205706"},"PeriodicalIF":5.3,"publicationDate":"2024-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-12-13DOI: 10.1016/j.wear.2024.205708
Yifei Wang , Xinchang Hu , Xuesheng Shi , Yang Yuan , Jie Gao , Youqiang Zhang
Unlike traditional progressive scratch tests, which gradually increase the load to the critical failure level, repeated scratch tests assess the failure behavior of a coating under the repeated application of subcritical loads. It typically provides a more accurate representation of the actual application conditions of a well-designed coating system, where overcritical conditions are not commonly encountered. In this study, the failure behavior of electroplated chrome coating under subcritical loads was evaluated through repeated scratch tests. The subcritical loads correspond to 20 %, 40 %, and 60 % of the critical load at which the coating experiences significant spalling. The results show that the coating exhibits different failure modes in repeated scratch tests compared to progressive scratch tests, in the following order: tensile crack, coating internal delamination, small spalling pit, and large spalling pit. The reason for this difference arises from the repeated loading in the repeated scratch test, and coating failure is influenced by the repeated frictional action of the indenter, which can be considered a cyclic wear test at low loads. The cutting and plasticity ratio shows that there are two deformation mechanisms, micro-plowing and micro-cutting, for scribing coating by the indenter and that the micro-cutting mechanism is dominant in the scribing process. As the load and the number of cycles increase, the proportion of micro-cutting continues to rise. Repeated scratch tests at subcritical loads provide a more comprehensive assessment of failure at different loads than progressive scratch tests and give clearer insights into the coating failure formation process.
{"title":"Failure mechanism analysis of electroplated chromium coating in repeated scratch tests under subcritical loads","authors":"Yifei Wang , Xinchang Hu , Xuesheng Shi , Yang Yuan , Jie Gao , Youqiang Zhang","doi":"10.1016/j.wear.2024.205708","DOIUrl":"10.1016/j.wear.2024.205708","url":null,"abstract":"<div><div>Unlike traditional progressive scratch tests, which gradually increase the load to the critical failure level, repeated scratch tests assess the failure behavior of a coating under the repeated application of subcritical loads. It typically provides a more accurate representation of the actual application conditions of a well-designed coating system, where overcritical conditions are not commonly encountered. In this study, the failure behavior of electroplated chrome coating under subcritical loads was evaluated through repeated scratch tests. The subcritical loads correspond to 20 %, 40 %, and 60 % of the critical load at which the coating experiences significant spalling. The results show that the coating exhibits different failure modes in repeated scratch tests compared to progressive scratch tests, in the following order: tensile crack, coating internal delamination, small spalling pit, and large spalling pit. The reason for this difference arises from the repeated loading in the repeated scratch test, and coating failure is influenced by the repeated frictional action of the indenter, which can be considered a cyclic wear test at low loads. The cutting and plasticity ratio shows that there are two deformation mechanisms, micro-plowing and micro-cutting, for scribing coating by the indenter and that the micro-cutting mechanism is dominant in the scribing process. As the load and the number of cycles increase, the proportion of micro-cutting continues to rise. Repeated scratch tests at subcritical loads provide a more comprehensive assessment of failure at different loads than progressive scratch tests and give clearer insights into the coating failure formation process.</div></div>","PeriodicalId":23970,"journal":{"name":"Wear","volume":"564 ","pages":"Article 205708"},"PeriodicalIF":5.3,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143140173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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