最新色国产精品精品视频,中文字幕日韩一区二区不卡,亚洲有码转帖,夜夜躁日日躁狠狠久久av,中国凸偷窥xxxx自由视频

The friction and wear properties of TC4 alloy surface were investigated by using ball/plane contact form of TRB3 friction testing machine. Using different upper samples which were TC4 ball, GCr15 steel ball and Si3N4 ceramic ball studied the friction scratches and wear characteristics of TC4 alloy under different normal forces. The friction scratch morphology was measured by 3D laser confocal microscope, and the energy wear models which could effectively predict the wear process were established to explore the change mechanism of contact state. The results indicated that the friction scratches of TC4 alloy whose length and width increased linearly with the increase of the load and depth fluctuates like a "sawtooth" were affected by the dislocation wall of indenter front and the adhesion particles of indenter offside, because the contact state of ball/plane changed to micro-plane/plane contact state with the enhance of the hardness of the upper sample. The cutting to plasticity ratio (fcp) which distributed to both sides of fcp =0.5 indicated the damage of TC4 alloy by indenter that were interacted by micro-ploughing and micro-cutting interacting to explain protective effect of process hardening phenomenon on the surface. In the meantime, the linear relationship between scratch hardness and surface roughness could predict the damage during material deformation.