Application of a Thermodynamically Based Wear Estimation Methodology

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
A. B. Aghdam ◽  
M. M. Khonsari
Keyword(s):  
Wear Rate ◽  
Temperature Rise ◽  
Experimental Tests ◽  
Sliding Contact ◽  
Dry Sliding ◽  
Loading Conditions

Entropic and energy-based approaches are employed for prediction of wear in dry sliding contact between crossed cylinders. The methodology requires measurement or estimation of the temperature rise in the sliding system. The results of experimental tests reported in literature in conjunction with measured degradation coefficients are used to examine the validity of the proposed methodology. The approach presented is shown to be capable of predicting the wear rate for different tribopairs and under different loading conditions.

scholarly journals Microstructural Characterization and Evaluation of Sliding Wear of Hastelloy C276 under Different Loading Conditions

2019 ◽  
Vol 8 (12) ◽  
pp. 2841-2845
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Frictional Force ◽  
Sliding Wear ◽  
Normal Load ◽  
Dry Sliding Wear ◽  
Material Surface ◽  
Dry Sliding ◽  
Loading Conditions ◽  
Sem Images

Hastelloy C276 is investigated for dry sliding wear against an EN 31 stainless steel (hardness 60 HRC) at 298 K. The tribological properties such as frictional force, coefficient of friction and the wear rate on the material surface at different sliding distance are examined under different loading conditions. In the dry wear test at 40 N load, the wear rate increased by 300% as compared to 10, 20, 30 N loading conditions. The experimental results indicated reduction in coefficient of friction values and thus an increase in the frictional force with the increase in normal load. SEM images of worn out surfaces confirm that the delamination and adhesion causes the material removal from the surface in dry sliding. Further, the analysis of the hardness characteristics of worn out surfaces shows surface hardening during sliding wear process under 40 N load

Dry Sliding Wear Behavior of 2218 Al-Alloy-Al2O3(TiO2) Hybrid Composites

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Vineet Tirth
Keyword(s):  
Wear Rate ◽  
Sliding Wear ◽  
Hybrid Composites ◽  
Wear Behavior ◽  
Dry Sliding Wear ◽  
Aged Alloy ◽  
Dry Sliding ◽  
Al Alloy ◽  
Mathematical Relationship ◽  
Sliding Distance

AA2218–Al2O3(TiO2) composites are synthesized by stirring 2, 5, and 7 wt % of 1:2 mixture of Al2O3:TiO2 powders in molten AA2218 alloy. T61 heat-treated composites characterized for microstructure and hardness. Dry sliding wear tests conducted on pin-on-disk setup at available loads 4.91–13.24 N, sliding speed of 1.26 m/s up to sliding distance of 3770 m. Stir cast AA2218 alloy (unreinforced, 0 wt % composite) wears quickly by adhesion, following Archard's law. Aged alloy exhibits lesser wear rate than unaged (solutionized). Mathematical relationship between wear rate and load proposed for solutionized and peak aged alloy. Volume loss in wear increases linearly with sliding distance but drops with the increase in particle wt % at a given load, attributed to the increase in hardness due to matrix reinforcement. Minimum wear rate is recorded in 5 wt % composite due to increased particles retention, lesser porosity, and uniform particle distribution. In composites, wear phenomenon is complex, combination of adhesive and abrasive wear which includes the effect of shear rate, due to sliding action in composite, and abrasive effect (three body wear) of particles. General mathematical relationship for wear rate of T61 aged composite as a function of particle wt % load is suggested. Fe content on worn surface increases with the increase in particle content and counterface temperature increases with the increase in load. Coefficient of friction decreases with particle addition but increases in 7 wt % composite due to change in microstructure.

Thermal Effects Due to Surface Films in Sliding Contact

1994 ◽  
Vol 116 (2) ◽  
pp. 238-245 ◽  
Author(s):  
Brian Vick ◽  
L. P. Golan ◽  
M. J. Furey
Keyword(s):  
Thermal Properties ◽  
Temperature Rise ◽  
Thermal Effects ◽  
Three Dimensional ◽  
Sliding Contact ◽  
Frictional Heat ◽  
Solution Technique ◽  
Surface Films ◽  
Thermal Coupling ◽  
Efficient Manner

The present work examines theoretically the influence of surface coatings on the temperatures produced by friction due to sliding contact. A generalized thermal model is developed which incorporates three-dimensional, transient heat transfer between layered media with thermal coupling at multiple, interacting contact patches. A solution technique based on a variation of the boundary element method is developed and utilized. The method allows for the solution of the distribution of frictional heat and the resulting temperature rise in an accurate yet numerically efficient manner. Results are presented showing the influence of film thickness, thermal properties, velocity, and contact area on the division of heat and surface temperature rise. The results show that a film with thermal properties different than those of the substrate can have a pronounced effect on the predicted temperature rise.

Design and Analysis of Automotive Bumper Covers in Transient Loading Conditions

2016 ◽  
Vol 715 ◽  
pp. 174-179 ◽  
Author(s):  
Chih Hsing Liu ◽  
Ying Chia Huang ◽  
Chen Hua Chiu ◽  
Yu Cheng Lai ◽  
Tzu Yang Pai
Keyword(s):  
Optimal Design ◽  
Numerical Model ◽  
Design Method ◽  
Experimental Tests ◽  
Cost Effective ◽  
Limited Range ◽  
Optimization Approach ◽  
Loading Conditions ◽  
Element Analysis ◽  
Design Guideline

This paper presents the analysis methods for design of automotive bumper covers. The bumper covers are plastic structures attached to the front and rear ends of an automobile and are expected to absorb energy in a minor collision. One requirement in design of the bumper covers is to minimize the bumper deflection within a limited range under specific loadings at specific locations based on the design guideline. To investigate the stiffness performance under various loading conditions, a numerical model based on the explicit dynamic finite element analysis (FEA) using the commercial FEA solver, LS-DYNA, is developed to analyze the design. The experimental tests are also carried out to verify the numerical model. The thickness of the bumper cover is a design variable which usually varies from 3 to 4 mm depending on locations. To improve the stiffness of the bumper, an optimal design for the bumper under a pre-defined loading condition is identified by using the topology optimization approach, which is an optimal design method to obtain the optimal layout of an initial design domain under specific boundary conditions. The outcome of this study provides an efficient and cost-effective method to predict and improve the design of automotive bumper covers.

scholarly journals Effect of Grain Size on the Friction-Induced Martensitic Transformation and Tribological Properties of 304 Austenite Stainless Steel

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1246
Author(s):  
Bo Mao ◽  
Shuangjie Chu ◽  
Shuyang Wang
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Martensitic Transformation ◽  
Wear Rate ◽  
Tribological Properties ◽  
Friction And Wear ◽  
Wear Behavior ◽  
304 Stainless Steel ◽  
Dry Sliding ◽  
Transformation Behavior

Friction and wear performance of austenite stainless steels have been extensively studied and show a close relationship with the friction-induced martensitic transformation. However, how the grain size and associated friction-induced martensitic transformation behavior affect the tribological properties of austenite steels have not been systematically studied. In this work, dry sliding tests were performed on an AISI 304 stainless steel with a grain size ranging from 25 to 92 μm. The friction-induced surface morphology and microstructure evolution were characterized. Friction-induced martensitic transformation behavior, including martensite nucleation, martensite growth and martensite variant selection and its effect on the friction and wear behavior of the 304 stainless steel were analyzed. The results showed that both the surface coefficient of friction (COF) and the wear rate increase with the grain size. The COF was reduced three times and wear rate was reduced by 30% as the grain size decreased from 92 to 25 μm. A possible mechanism is proposed to account for the effect of grain size on the tribological behavior. It is discussed that austenite steel with refined grain size tends to suppress the amount of friction-induced martensitic transformed and significantly alleviates both the plowing and adhesive effect during dry sliding.

Specific Wear Rate of Kenaf Epoxy Composite and Oil Palm Empty Fruit Bunch (OPEFB) Epoxy Composite in Dry Sliding

2012 ◽  
Vol 58 (2) ◽  
Author(s):  
Salmiah Kasolang ◽  
Mohamad Ali Ahmad ◽  
Mimi Azlina Abu Bakar ◽  
Ahmad Hussein Abdul Hamid
Keyword(s):  
Wear Rate ◽  
Oil Palm ◽  
Epoxy Composite ◽  
Fibre Composite ◽  
Specific Wear Rate ◽  
Dry Sliding ◽  
Empty Fruit Bunch ◽  
Sliding Velocity ◽  
Fiber Size ◽  
Wear Tests

This paper presents an experimental investigation carried out to compare specific wear rate and surface morphology between two types of natural fibres namely kenaf and oil palm empty fruit bunch (OPEFB). Kenaf fibres were received in long fiber size and OPEFB in different sizes (100, 125, 180 and 250 μm). Both materials were mixed with the epoxy resin to produce epoxy composites. Wear tests were carried out using Abrasion Resistance Tester in dry sliding condition. These tests were performed at room temperature for different loads and at a constant sliding velocity of 1.4m/s. Based on the results, the specific wear rate of Kenaf Fibre composite starts to converge to one similar value beyond 6km distance. In the case of OPEFB epoxy composite, it was found the fiber size of 100 um has produced the highest specific wear rate.

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