scholarly journals Influence of Contact Stress on Surface Microstructure and Wear Property of D2/U71Mn Wheel-Rail Material

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3268 ◽  
Author(s):  
Chun-Peng Liu ◽  
Xiu-Juan Zhao ◽  
Peng-Tao Liu ◽  
Jin-Zhi Pan ◽  
Rui-Ming Ren
Keyword(s):  
Plastic Deformation ◽  
Wear Rate ◽  
Contact Stress ◽  
Wear Mechanism ◽  
Fatigue Cracks ◽  
Surface Microstructure ◽  
Wear Property ◽  
Fatigue Wear ◽  
Deformation Layer ◽  
Wear Tests

To investigate the relationship between surface microstructure and wear mechanism in D2/U71Mn wheel-rail material under different contact stress conditions, rolling wear tests using a GPM-40 wear machine to simulate the wheel-rail operation was performed. After wear tests, an optical microscope (OM), scanning electron microscope (SEM) and micro-hardness testers were used to characterize the microstructure and fatigue wear cracks. The results show that the thickness of the plastic deformation layer and surface hardness is increased with the increase of contact stress. Under high contact stress condition (1200 MPa), the severe plastic deformation layer led to the formation of fatigue wear of wheel-rail samples. Under a contact stress of 700 MPa, the wear mechanism of samples is adhesive wear and wear rate is low. With the increase of contact stress, the fatigue cracks are gradually severe. Under a contact stress of 1200 MPa, the wear mechanism of samples becomes fatigue wear and the fatigue wear cracks cause the increase of wear rate. The fatigue wear can accelerate the wear failure of wheel-rail samples. The fatigue wear cracks of wheel samples are severer than that of rail samples due to both the rate of plastic strain and the content of proeutectoid ferrite.

Wear Behaviour of Al-1050 Alloy Processed by Severe Plastic Deformation

2010 ◽  
Vol 667-669 ◽  
pp. 1101-1106 ◽  
Author(s):  
Chuan Ting Wang ◽  
Nong Gao ◽  
Robert J.K. Wood ◽  
Terence G. Langdon
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Wear Rate ◽  
Wear Mechanism ◽  
Sliding Wear ◽  
Wear Behaviour ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Oxidation Wear ◽  
Wear Tests

An Al-1050 alloy was processed by ECAP and HPT, respectively. Dry sliding wear tests were conducted on the as-received and SPD-processed samples under various sliding conditions. A comparison of wear rate indicated that SPD processing decreased the wear resistance. Two main wear mechanisms were observed. The initial wear stage was dominated by severe platelet wear mechanism and later wear was dominated by an oxidation wear mechanism. The results show the severe wear stage of SPD-processed Al-1050 is much longer than that of the as-received Al-1050, which is attributed to the loss of work hardening capacity after SPD processing.

Wear Mechanism and Self Lubrication of Engineering Ceramics at Elevated Temperatures

2008 ◽  
Vol 368-372 ◽  
pp. 1092-1095 ◽  
Author(s):  
Han Ning Xiao ◽  
Ji Xiang Yin ◽  
Tetsuya Senda
Keyword(s):  
Wear Rate ◽  
Wear Mechanism ◽  
Friction And Wear ◽  
Elevated Temperatures ◽  
Testing Temperature ◽  
Nano Particles ◽  
Wear Loss ◽  
Pressure Oxidation ◽  
Wear Tests ◽  
Friction And Wear Tests

Friction and wear tests of Al2O3 and SiC were conducted from room temperature to 1200°C both in air and in vacuum. Results show that the wear mechanism of Al2O3 is dominated by micro fracture, debris abrasive and delamination at temperatures below 600 °C, while is controlled by plastic deformation and recrystallization among 600~1200 °C, resulting in an obvious decrease of wear loss. The wear rate and surface microstructure of SiC are closely depending on the testing temperature, atmosphere and contact pressure. Oxidation of SiC at elevated temperatures plays important role on the wear rate. Self lubrication of both Al2O3 and SiC at high temperatures was observed, which is mainly depending on the formation of a specific surface layer composed of nano-particles or very thin glassy film.

scholarly journals Dry Rolling/Sliding Wear of Bainitic Rail Steels under Different Contact Stresses and Slip Ratios

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4678
Author(s):  
Jiapeng Liu ◽  
Yingqi Li ◽  
Yinhua Zhang ◽  
Yue Hu ◽  
Lubing Shi ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Abrasive Wear ◽  
Contact Stress ◽  
Wear Mechanism ◽  
Rolling Contact Fatigue ◽  
Contact Fatigue ◽  
Rolling Contact ◽  
Wear Loss ◽  
Fatigue Wear ◽  
Slip Ratio

This study aims to deeply understand the effect of contact stress and slip ratio on wear performances of bainitic rail steels. The results showed that the wear loss increased as the contact stress and slip ratio increased. Based on the surface damage morphology and microstructural analyses, it revealed that the rolling contact fatigue wear mechanism played a significant role under the low slip ratio, but the dominant wear mechanism transferred to the abrasive wear at the high slip ratio. Meanwhile, the bainitic steel specifically presented worse wear resistance under the abrasive wear mode. Compared with the influence of a slip ratio, the increase in contact stress led to severer plastic flows and contributed to the propagation of cracks. In addition, the contact stress and slip ratio had the opposite effect on the friction coefficient, that is, the friction coefficient of bainitic steels behaved the inverse proportion with the contact stress, but positive proportion with the slip ratio. At last, the increase in slip ratio had more significant effect on the reduction of retained austenite (RA) than the enlargement of contact stress due to the fact that the RA would probably be removed before the martensitic transformation occurred under the abrasive wear mechanism.

The Simulation of Sliding Wear by Cyclic Plastic Deformation Under Combined Stresses

1984 ◽  
Vol 106 (3) ◽  
pp. 248-252 ◽  
Author(s):  
R. Glardon ◽  
S. Chavez ◽  
I. Finnie
Keyword(s):  
Plastic Deformation ◽  
Wear Rate ◽  
Sliding Wear ◽  
Mechanical Test ◽  
Material Behavior ◽  
Cyclic Plastic ◽  
Combined Stresses ◽  
Cyclic Plastic Deformation ◽  
Future Work ◽  
Wear Tests

A mechanical test which is believed to simulate the conditions occurring in sliding wear is described. It involves the cyclic plastic deformation of metals under combined compression and shear. The results of tests on six alloys are reported and correlated with those from wear tests. On this basis, an expression is proposed for the sliding wear rate which is based on material behavior during cyclic plastic deformation and involves three material properties. The implications of this expression for the wear rate are discussed and directions for future work are suggested.

scholarly journals Microstructure and Properties of AA6061/SiCp Composites Sintered under Ultra High-Pressure

2020 ◽  
Vol 10 (20) ◽  
pp. 7363
Author(s):  
Lei Xu ◽  
Erkuo Yang ◽  
Yasong Wang ◽  
Changyun Li ◽  
Zhiru Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Wear Property ◽  
Ultra High Pressure ◽  
High Pressure Sintering

Ultra high-pressure sintering (UHPS) was used to prepare AA6061/SiCp composites with different contents and the effect of sintering temperatures on microstructure and mechanical properties was investigated in this study. The results showed that a uniform distribution of nano-SiC particles (N-SiCp) is obtained by the UHPS method. With the increase in N-SiCp contents, the higher hardness and better wear resistance could be inspected. The interfacial reactions and Al4C3 phase appeared above 550 °C. The relative density of composites first increased and then decreased; with the temperature raising it reached 99.58% at 600 °C. The hardness and wear property showed the same trend with the hardness reaching 52 HRA and wear rate being 1.0 × 10−6 g/m at 600 °C. Besides, the wear mechanism of the composites is mainly composed of abrasive wear and adhesive wear.

Wear Resistance of Cu10Al5Fe5Ni Alloy

2015 ◽  
Vol 817 ◽  
pp. 571-576
Author(s):  
Jun Tao Zou ◽  
Chan Wang ◽  
Yang Li ◽  
Xian Hui Wang ◽  
Shu Hua Liang
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Cast Alloy ◽  
Lubricating Oil ◽  
Fatigue Wear ◽  
Lubrication Condition ◽  
Increasing Temperature ◽  
Scanning Electron

The effect of ambient temperature, materials state and lubrication condition on wear resistance of Cu10Al5Fe5Ni alloy was investigated. The wear surface morphology was characterized by a scanning electron microscope (SEM), and the wear mechanism was discussed as well. The results show that the friction coefficient of Cu10Al5Fe5Ni alloy increases and then decreases with increasing temperature. The wear rate of the Cu10Al5Fe5Ni alloy after solid solution and ageing treatment is less than that of the as-cast alloy, and the wear rate of Cu10Al5Fe5Ni alloy reduces dramatically from 5.31×10-5 mm3 / (m· N) into 1.80×10-6 mm3 / (m·N) after adding lubricating oil. At elevated temperature, the prior wear mechanism is the fatigue wear, accompanying by slight abrasive wear and adhesive wear for the aged Cu10Al5Fe5Ni alloy.

Effect of contact stress on the tribology behaviors of PTFE/316L seal pairs under various abrasive-contained conditions

2020 ◽  
pp. 135065012093751
Author(s):  
Ming-xue Shen ◽  
Bo Li ◽  
De-hui Ji ◽  
Xiao-Rong He ◽  
Xiu-zhou Lin ◽  
...  
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Contact Stress ◽  
Wear Mechanism ◽  
Considerable Effect ◽  
Contact Stresses ◽  
The Coefficient Of Friction ◽  
Three Body ◽  
Size Threshold ◽  
Invasion Behavior

This study focuses on the tribological characteristics of polytetrafluoroethylene rubbing against 316L stainless steel in the presence of various Al2O3 abrasive particles. The ranges of the contact stresses and abrasive sizes were 2.50–5.01 MPa and 2.0–230 µm, respectively. The evolution of the coefficient of friction, abrasive invasion behavior and damage characteristics on worn surfaces, and the transformation of damage mechanisms under different contact stresses are summarized. Results demonstrate that contact stress exerts a considerable effect on abrasive invasion behavior, the coefficient of friction trends become complicated at low contact stress. With decreasing particle sizes under a contact stress of 2.50 MPa, the wear failure changes from two-body wear to three-body wear, or two wear behaviors exist simultaneously. As contact stress increases, the wear mechanism is gradually simplified. The particle size threshold that causes the change of the wear mechanism is also gradually reduced. The wear rate of polytetrafluoroethylene has no linear relationship with abrasive size, whereas wear increases with contact stress. Under 2.50 MPa conditions, the particles easily invade the tribo-interface in the friction process, thus increasing the wear rate of the metallic counterpart. In addition, with increases contact stress, the polytetrafluoroethylene material transfers to the counterface, and local adhesion occurs. When the contact stress is increased to 5.01 MPa, polytetrafluoroethylene even shows an obvious creep.

Wear Mechanism and Self Lubrication of Engineering Ceramics at Elevated Temperatures

2012 ◽  
Vol 554-556 ◽  
pp. 721-725
Author(s):  
Hao Liu ◽  
Ye Bin Cai
Keyword(s):  
Wear Rate ◽  
Wear Mechanism ◽  
Friction And Wear ◽  
Elevated Temperatures ◽  
Testing Temperature ◽  
Nano Particles ◽  
Wear Loss ◽  
Pressure Oxidation ◽  
Wear Tests ◽  
Friction And Wear Tests

Friction and wear tests of Al2O3 and SiC were conducted from room temperature to 1200 °C both in air and in vacuum. Results show that the wear mechanism of Al2O3 is dominated by micro fracture, debris abrasive and delamination at temperatures below 600 °C, while is controlled by plastic deformation and recrystallization among 600~1200 °C, resulting in an obvious decrease of wear loss. The wear rate and surface microstructure of SiC are closely depending on the testing temperature, atmosphere and contact pressure. Oxidation of SiC at elevated temperatures plays important role on the wear rate. Self lubrication of both Al2O3 and SiC at high temperatures was observed, which is mainly depending on the formation of a specific surface layer composed of nano-particles or very thin glassy film.

scholarly journals Detecting Safety Zone Drill Process Parameters for Uncoated HSS Twist Drill in Machining GFRP Composites by Integrating Wear Rate and Wear Transition Mapping

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Sathish Rao Udupi ◽  
Lewlyn Lester Raj Rodrigues
Keyword(s):  
Wear Rate ◽  
Tool Wear ◽  
Abrasive Wear ◽  
Process Parameters ◽  
Wear Mechanism ◽  
High Speed Steel ◽  
Gfrp Composites ◽  
Safety Zone ◽  
Fatigue Wear ◽  
Wear Mechanism Map

The previous research investigations informed that the tool wear of any machining operation could be minimized by controlling the machining factors such as speed, feed, geometry, and type of cutting tool. Hence the present research paper aims at controlling the process parameters to minimize the drill tool wear, during the machining of Glass Fiber Reinforced Polymer (GFRP) composites. Experiments were carried out to find the tool wear rate and a wear mechanism map of uncoated High Speed Steel (HSS) drill of 10 mm diameter was developed for the drilling of GFRP composite laminates. The surface micrograph images on the drill land surface displayed dominant wear mechanisms induced on HSS drill during machining of GFRP and they were found to be adhesive wear, adhesive and abrasive wear, abrasive wear, and diffusion and fatigue wear. A “safety wear zone” was identified on the wear mechanism map, where the minimum tool wear of the HSS drill occurs. From the safety zone boundaries, it was inferred that the drill spindle speed should be set between 1200 and 1590 rpm and feed rate must be set within a range of 0.10–0.16 mm/rev for GFRP work and HSS tool combination to enhance the service life of 10 mm HSS drills and to minimize the tool wear.

Erosion Wear Property of Surface Diffusion Alloyed Coatings on Magnesium Alloy

2011 ◽  
Vol 682 ◽  
pp. 217-223
Author(s):  
You Ping Ma ◽  
Xiu Lan Li ◽  
Lei Yang ◽  
Xi Peng He
Keyword(s):  
Wear Resistance ◽  
Magnesium Alloy ◽  
Surface Diffusion ◽  
Wear Mechanism ◽  
Wear Property ◽  
Erosion Wear ◽  
Erosion Properties ◽  
The Difference ◽  
Wear Tests ◽  
Better Than

Erosion wear tests under different erosion slurry mediums were carried out to investigate erosion properties of the treated samples of ZM5 magnesium alloy by surface diffusion alloying processing (SDAP).The result indicated that the micro-hardness (HV172) near the surface of alloyed specimen was about twice more than that of its substrate(HV82) after treated at 390°C for 8h.The erosion wear resistance β (0.68×104 mm2/g) of the treated specimen was better than that of untreated specimen (0.48×104mm2/g) under the conditions of erosion slurry of oil and quartz. The difference of erosion wear resistance between them was primary due to cutting wear mechanism. While erosion mediums was changed to the slurry of water and quartz, the wear resistance β of the treated specimen increase up to 0.24×104 (mm2/g), and that of the untreated specimen was only 0.09×104 (mm2/g),the difference between them resulted from corrosion wear mechanism predominating, which worsen the erosion wear resistance β.

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