Dynamic Frictions between AISI 316L and 3MTM TrizactTM Structured Abrasive Belts during Mirror-Like Polishing

2015 ◽  
Vol 642 ◽  
pp. 227-230
Author(s):  
Bo Sung Yang ◽  
Jin Cheng Yeh ◽  
Ming Shin Tsai ◽  
Jing Lun Liao ◽  
Shun Yi Wu ◽  
...  

polishing is an essential process for deriving of the mirror-like surface of the AISI 316L stainless steel to minimize the surface roughness. Sliding, plowing and cutting, the fundamental mechanisms of abrasive machining, are occurred during the polishing and then would decrease the roughness on the surface. By 3MTM TrizactTM structured abrasive belts, the previous stainless steel are polished. Pyramid arrays containing the abrasives and epoxy formed on the belt give the abrasive machining. The glass transition and degradation temperatures of epoxy are about 150 and 250 degrees, respectively. The friction coefficient between the AISI 316L workpiece and 3MTM TrizactTM structured abrasive belt under different rotational speed may affect the polishing efficiency and the cost. The mechanism of the abrasive machining includes the sliding, plowing and cutting while the previous two are preferred during polishing. By 3MTM TrizactTM Structured Abrasive belts, the grit sizes are #800 and #2000, the MIM stainless steel cases are polished. The contact dynamic friction coefficient induces a higher specific polishing energy, the polishing temperature is thus increased. Deriving the friction coefficient is therefore important for stainless steel polishing. Experimental results indicate that the dynamic friction coefficient decreases respect to the rotational speed and the press-on force of workpiece. The coefficients of friction of all the workpieces under different tangential velocity are in a large range of 1.2–5.6, but the friction coefficient of the tangential velocity of 23.56 m/sec shows slightly variation even press-on force in 5 Newtons or in 20 Newtons.

2021 ◽  
Vol 69 (3) ◽  
Author(s):  
Gianluca Costagliola ◽  
Tobias Brink ◽  
Julie Richard ◽  
Christian Leppin ◽  
Aude Despois ◽  
...  

AbstractWe report experimental measurements of friction between an aluminum alloy sliding over steel with various lubricant densities. Using the topography scans of the surfaces as input, we calculate the real contact area using the boundary element method and the dynamic friction coefficient by means of a simple mechanistic model. Partial lubrication of the surfaces is accounted for by a random deposition model of oil droplets. Our approach reproduces the qualitative trends of a decrease of the macroscopic friction coefficient with applied pressure, due to a larger fraction of the micro-contacts being lubricated for larger loads. This approach relates direct measurements of surface topography to realistic distributions of lubricant, suggesting possible model extensions towards quantitative predictions.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Qin Lian ◽  
Chunxu Yang ◽  
Jifei Cao

The transition between static and kinetic frictions of steel/shale pairs has been studied. It was found that the coefficient of friction decreased exponentially from static to dynamic friction coefficient with increasing sliding displacement. The difference between static and dynamic friction coefficients and the critical distance Dc under the dry friction condition is much larger than that under the lubricated condition. The transition from static to dynamic friction coefficient is greatly affected by the normal load, quiescent time, and sliding velocity, especially the lubricating condition. Maintaining continuous lubrication of the contact area by the lubricant is crucial to reduce or eliminate the stick-slip motion. The results provide an insight into the transition from static to dynamic friction of steel/shale pairs.


Author(s):  
Xiangzhen Xue ◽  
Jipeng Jia ◽  
Qixin Huo ◽  
Junhong Jia

To investigate the fretting wear of involute spline couplings in aerospace, rack-plane spline couplings rather than the conventional involute spline couplings in aerospace were used to conduct tribological experiments, and it was assumed that the rack-plane spline couplings exhibit consistent contact stress with the real involute spline couplings in aerospace. The relationships among the static friction coefficient, dynamic friction coefficient, and fretting friction coefficient were established via tribological experiments, as well as the fretting-wear mechanism of the rack-plane spline couplings was examined. A fretting-wear estimation model based on the fretting-wear mechanism was developed. By applying the modified Archard equation and Arbitrary Lagrangian–Eulerian adaptive, mesh smoothing algorithm of Abacus was used. According to our experimental results, the fretting wear of the rack-plane spline couplings consisted primarily of abrasive wear, oxidative wear, and adhesive wear. For both, lubrication and non-lubrication settings, the fretting friction coefficient of 18CrNi4A steel (0.27) fluctuated between 0.12 (dynamic friction coefficient) and 0.35 (static friction coefficient). The fretting-wear results estimated via numerical prediction were consistent with the experimental results. When sm (vibration amplitude) was 20, 35, and 50 µm, the most difference in the fretting wear between the experimental results and numerical estimation was 0.001, 0.0007, and 0.001 mm, respectively. Therefore, the proposed model provides a method for accurate estimation of the fretting-wear. Additionally, the model contributes to the precise design of involute spline couplings in aerospace.


Author(s):  
Xi Shi ◽  
Andreas A. Polycarpou

As the size of contacting and sliding tribosystems decrease, intermolecular or adhesive forces become significant partly due to nanometer size surface roughness. The presence of adhesion has a major influence on the interfacial contact and friction forces as well as the microtribosystem dynamics and thus influences the overall dynamic friction behavior. In this paper, a dynamic friction model that explicitly includes adhesion, interfacial damping and the system dynamics for realistic rough surfaces was developed. The results show that the amplitude and mean value of the time varying normal contact and friction forces increase in the presence of adhesion under continuous contact conditions. Also, due to the attractive nature of adhesion, its presence delays or eliminates the occurrence of loss of contact. Furthermore, in the presence of significant adhesion, dynamic friction behavior is significantly more complicated compared to the no adhesion case, and the dynamic friction coefficient predictions may be misleading. Thus, it is more appropriate to discuss dynamic friction force instead of dynamic friction coefficient under dynamic conditions.


2013 ◽  
Vol 401-403 ◽  
pp. 320-325
Author(s):  
Ming Ming Qiu ◽  
Han Zhao ◽  
Fa Ming Sha

Introduce the dynamic friction coefficient of clutch friction plate. Establish Mathematical model of starting process, carried out vibration analysis for frictional sliding process systematically, validated the analysis using Matlab/simulink software. Meanwhile, compared with the starting process by static friction coefficient. The results show that using dynamic friction coefficient to analyse starting process conforms to the actual working condition.


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