A Sliding Wear Model for Partial-EHL Contacts

1991 ◽  
Vol 113 (1) ◽  
pp. 134-141 ◽  
Author(s):  
Shifeng Wu ◽  
H. S. Cheng
Keyword(s):  
Wear Rate ◽  
Wear Mechanism ◽  
Sliding Wear ◽  
Contact Region ◽  
Contact Temperature ◽  
Hertzian Contact ◽  
Asperity Contact ◽  
Wear Model ◽  
Actual Surface ◽  
Transitional Phenomenon

A sliding wear model has been developed for partial-EHL contacts, in which both the thermal desorption wear mechanism at low asperity contact temperature and the oxidative wear mechanism at elevated asperity contact temperature are considered. To include micro-EHL effects, digitized actual surface roughness profiles are used in simulating two contacting rough surfaces, and in obtaining the asperity contact area and asperity contact temperature distributions within a Hertzian contact region. Wear measurements in a two-disk machine configuration have been made over a comprehensive range of slide-to-roll ratios. The experimental results show a continuous decrease in wear rate with the increase in slide-to-roll ratio when the slide-to-roll ratio is relatively small, and a drastic rise in wear rate when slide-to-roll ratio is further increased. The experimental wear rate curve as a function of slide-to-roll ratio verifies the model prediction. The drastic rise in wear rate with the increase in slide-to-roll ratio in the range of slide-to-roll ratio beyond unity seems to suggest that a transitional phenomenon exists in the relation between wear rate and slide-to-roll ratio.

Numerical Prediction of Surface Wear and Roughness Parameters During Running-In for Line Contacts Under Mixed Lubrication

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Yazhao Zhang ◽  
Alexander Kovalev ◽  
Noriyuki Hayashi ◽  
Kensuke Nishiura ◽  
Yonggang Meng
Keyword(s):  
Friction Coefficient ◽  
Contact Region ◽  
Mixed Lubrication ◽  
Asperity Contact ◽  
Wear Particles ◽  
Wear Model ◽  
Wear Process ◽  
Line Contacts ◽  
Lubrication Condition ◽  
Initial Line

A stochastic model for predicting the evolutions of wear profile and surface height probability density function (PDF) of initial line contacts during running-in under mixed lubrication condition is presented. A numerical approach was developed on the basis of stochastic solution of mixed lubrication, which combined the Patir and Cheng's average flow model for calculation of the hydrodynamic pressure and the Kogut and Etsion's (KE) rough surface contact model for calculation of the asperity contact pressure. The total friction force was assumed to be the sum of the boundary friction at the contact asperities and the integration of viscous shear stress in the hydrodynamic region. The wear depth on the contact region was estimated according to the modified Archard's wear model using the asperity contact pressure. Sugimura's wear model was modified and used to link the wear particle size distribution and the variation of surface height PDF during wear. In the wear process, the variations of profile and surface height PDF of initial line contacts were calculated step by step in time, and the pressure distribution, friction coefficient, and wear rate were updated consequently. The effect of size distribution of wear particles on the wear process was numerically investigated, and the simulation results showed that the lubrication condition in which small wear particles are generated from the asperity contact region is beneficial to reduce friction coefficient and wear rate, and leads to a better steady mixed lubrication condition.

Study on Wear Mechanism and Contact Temperature against Dry Sliding Wear of Ni-Al2O3 Nanocomposite Coating

2020 ◽  
Vol 79 (3) ◽  
pp. 139-143
Author(s):  
Challakere Ramadas Raghavendra ◽  
Satyappa Basavarajappa ◽  
Irappa Sogalad ◽  
Kishan Naik
Keyword(s):  
Wear Mechanism ◽  
Sliding Wear ◽  
Nanocomposite Coating ◽  
Contact Temperature ◽  
Dry Sliding Wear ◽  
Dry Sliding

Wear Behavior of Laser-Hardened GCr15 Steel under Lubricated Sliding Conditions

2009 ◽  
Vol 628-629 ◽  
pp. 697-702 ◽  
Author(s):  
Sheng Lei ◽  
Quan Kun Liu ◽  
Yu Ping Liu ◽  
Heng Li
Keyword(s):  
Wear Resistance ◽  
Surface Modification ◽  
Wear Rate ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Sliding Wear ◽  
Laser Surface ◽  
Ferrous Alloys ◽  
Gcr15 Steel ◽  
Lubricated Sliding

Microstructure, microhardness and tribological properties of laser hardened GCr15 steel were investigated in this paper. The wear resistance under lubricated sliding conditions was compared between specimens treated with laser and those of conventionally hardened. The tribological properties of laser surface-quenched GCr15 steel specimens were slightly better due to the effects of the microstructure hardening, high hardness and toughness, with the wear rate (in the order of 10-6mg/Nm) lower than that of the conventionally treated specimens. At the steady state, the frictional coefficient of laser-treated samples had no obvious difference from that of the conventionally treated samples. The wear mechanism for both cases was similar, generally involved surface fatigue wear and slight abrasion wear. LeiQ.K. Liu S. Lei Introduction H. Li In recent years, among the various surface modification methods, laser-induced surface modification has gained much attention for achieving the desired properties for applications[1]. This method is mainly used for ferrous alloys which undergo martensitic transformation and thus form a very hard surface layer with negligible surface roughness and distortion[2]. Some ideas demonstrated that the wear rate at a particular contact pressure can be strongly influenced by the microstructure of the steel, but there is also contrary idea that under the conditions of mild wear, the microstructural constituents of steels have no significant influence on the wear rate, although they affect the rate of severe wear. Previous studies of the authors demonstrated that under the dry sliding wear conditions, laser surface-hardened specimens of ferrous alloys exhibited enhanced wear resistance than conventionally hardened specimens. The aim of the study is to investigate the lubricated sliding wear behaviors of laser surface hardened GCr15 steel specimens and to compare the effect of the different microstructure compositions for laser transformation hardening with those of conventionally hardened and quenched. Moreover, the wear properties of the GCr15 steel and its corresponding wear mechanism under the lubricated wear conditions will also be studied.

Sliding Wear and Metal Transfer Under Unlubricated Conditions

1959 ◽  
Vol 81 (1) ◽  
pp. 67-77 ◽  
Author(s):  
R. P. Steijn
Keyword(s):  
Wear Rate ◽  
Wear Mechanism ◽  
Surface Finish ◽  
Sliding Wear ◽  
Metal Transfer ◽  
Hardened Steel ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Finish Material ◽  
Back Transfer

To provide further information on dry sliding wear and the accompanying metal transfer, wear experiments of radioactive brass rings against hardened steel have been conducted in a ring tester. The effect on metal transfer of sliding speed, surface finish, material of the harder surface, and the presence of slots in the steel ring have been investigated. Tests have also been conducted in argon atmospheres to exclude oxidation. Wear of brass on brass has been investigated by using radioactive rings against inactive rings. Results indicate a complex wear mechanism in which transfer, back transfer, and removal of transferred material are intermediate steps, and in which the determining step in wear rate is governed by the geometry of the rings rather than the apparent area of contact.

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.

A Dynamic Wear Model for Micro-Grooved Water-Lubricated Bearings Under Transient Mixed Lubrication Condition

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Guo Xiang ◽  
Yanfeng Han ◽  
Tao He ◽  
Jiaxu Wang ◽  
Ke Xiao
Keyword(s):  
Friction Coefficient ◽  
Sliding Wear ◽  
Boundary Friction ◽  
Radial Clearance ◽  
Asperity Contact ◽  
Wear Coefficient ◽  
Wear Model ◽  
Surface Parameters ◽  
Simulation Results ◽  
Dynamic Wear

Abstract The study presents a dynamic wear model for micro-grooved water-lubricated bearings considering the transient mixed elastohydrodynamic lubrication (mixed-EHL) condition. In the established model, the modified Archard wear model and the mixed-EHL model are bridged to study the transient interdependent relationship between the sliding wear behavior and the mixed-EHL performance. In order to consider the effect of the transient mixed-EHL performance on the sliding wear, the Archard model is extended to include the time-varying wear coefficient based on the fatigue concept. To verify the presented model, the comparisons with the experimental results available in the literatures have been conducted. In this study, the evolution of the wear and mixed-EHL performance distribution over time is predicted, and the impact of the radial clearance, boundary friction coefficient, and surface parameters on the numerical predictions is evaluated. The simulation results reveal that the worn region moves toward the rotational direction slowly. The simulation results also reveal that the wear rate and the wear coefficient first decrease considerably, and then decrease gently, and the sliding wear geometry promotes the hydrodynamic effects and reduces the asperity contact during the operation. Furthermore, the parametric study demonstrates that dynamic wear and mixed-EHL performance is sensitive to the radial clearance, boundary friction coefficient, and surface parameters.

A Fundamental Tribological Study of Ti/Al2O3 Contact in Sliding Wear

1989 ◽  
Vol 111 (3) ◽  
pp. 504-509 ◽  
Author(s):  
H. Hong ◽  
W. O. Winer
Keyword(s):  
Wear Rate ◽  
Single Crystal ◽  
Chemical Reaction ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Theoretical Approach ◽  
Sliding Wear ◽  
Sliding Contact ◽  
Tribological Study ◽  
Friction Heating

The tribological properties of titanium in sliding contact with single crystal Al2O3 were studied to investigate wear mechanism associated with tribo-chemical reaction due to friction heating. Oxidational wear was observed. A theoretical approach to predict the wear rate of titanium was also studied.

scholarly journals FRICTION AND WEAR RESPONSE OF TiB2-B4C CERAMICS

2013 ◽  
Vol 4 (2) ◽  
Author(s):  
Yeczain Perez ◽  
Koen Bonny ◽  
Patrick De Baets ◽  
M. H. Staia ◽  
P.D. Neis ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Wear Debris ◽  
Sliding Wear ◽  
Friction And Wear ◽  
Room Temperature ◽  
Hertzian Contact ◽  
Sliding Velocity ◽  
Dry Conditions ◽  
Wear Response

  Rotating sliding wear experiments on TiB2-B4C have been conducted at room temperature (25 °C) in dry conditions according to the ASTMG99-95a standard. SiC balls were used as static counterpart. The disk specimens were surface finished by polishing. The tests were performed using different rotating sliding speeds from 0.1 up to 1.5 m/s with a mean Hertzian contact pressure of 1.2 GPa. Balls and disk specimens were analyzed by 2-D and 3-D surface topography, SEM and optical microscopy. The experimental results demonstrated that the sliding velocity influences both friction coefficient and wear rate values of TiB2-B4C ceramics. It was shown, that the wear rate varied between 3.64E-7 to 8.43E-7 mm3/Nm. Wear mechanisms such as polishing, abrasion and wear debris formation have been identified by means of SEM and EDX technique.

Prediction of Steady State Adhesive Wear in Spur Gears Using the EHL Load Sharing Concept

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
S. Akbarzadeh ◽  
M. M. Khonsari
Keyword(s):  
Steady State ◽  
Wear Rate ◽  
Thermal Effects ◽  
Sliding Wear ◽  
Adhesive Wear ◽  
Load Sharing ◽  
Spur Gears ◽  
Wear Model ◽  
Wear Calculation ◽  
Simulation Results

The concept of load sharing between asperities and fluid film is applied in conjunction with lubricated sliding wear formulation proposed by Wu and Cheng (1991, “A Sliding Wear Model for Partial-EHL Contacts,” ASME J. Tribol., 113, pp. 134–141; 1993, “Sliding Wear Calculation in Spur Gears,” ASME J. Tribol., 115, pp. 493–500) to predict the steady state adhesive wear in gears. Thermal effects are included using a simplified thermoelastohydrodynamic analysis. The prediction of the model is verified by comparing simulation results with published experimental data pertinent to steady state wear rate. The main advantages of this method are the accuracy and the remarkable computational efficiency. The results of parametric simulation study are presented to investigate the effect of speed and surface roughness on a portion of load carried by asperities and wear rate.

scholarly journals Sliding Wear of Conventional and Suspension Sprayed Nanocomposite WC-Co Coatings: An Invited Review

2021 ◽  
Author(s):  
R. Ahmed ◽  
O. Ali ◽  
C. C. Berndt ◽  
A. Fardan
Keyword(s):  
Wear Rate ◽  
Thermal Spray ◽  
Sliding Wear ◽  
Failure Modes ◽  
Thermal Spray Coatings ◽  
Annual Growth Rate ◽  
Total Energy Consumption ◽  
Wear Performance ◽  
Wear Rates ◽  
Spray Coatings

AbstractThe global thermal spray coatings market was valued at USD 10.1 billion in 2019 and is expected to grow at a compound annual growth rate of 3.9% from 2020 to 2027. Carbide coatings form an essential segment of this market and provide cost-effective and environmental friendly tribological solutions for applications in aerospace, industrial gas turbine, automotive, printing, oil and gas, steel, and pulp and paper industries. Almost 23% of the world’s total energy consumption originates from tribological contacts. Thermal spray WC-Co coatings provide excellent wear resistance for industrial applications in sliding and rolling contacts. Some of these applications in abrasive, sliding and erosive conditions include sink rolls in zinc pots, conveyor screws, pump housings, impeller shafts, aircraft flap tracks, cam followers and expansion joints. These coatings are considered as a replacement of the hazardous chrome plating for tribological applications. The microstructure of thermal spray coatings is however complex, and the wear mechanisms and wear rates vary significantly when compared to cemented WC-Co carbides or vapour deposition WC coatings. This paper provides an expert review of the tribological considerations that dictate the sliding wear performance of thermal spray WC-Co coatings. Structure–property relationships and failure modes are discussed to grasp the design aspects of WC-Co coatings for tribological applications. Recent developments of suspension sprayed nanocomposite coatings are compared with conventional coatings in terms of performance and failure mechanisms. The dependency of coating microstructure, binder material, carbide size, fracture toughness, post-treatment and hardness on sliding wear performance and test methodology is discussed. Semiempirical mathematical models of wear rate related to the influence of tribological test conditions and coating characteristics are analysed for sliding contacts. Finally, advances for numerical modelling of sliding wear rate are discussed.

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