滑动速度对织构化表面润滑状态的影响

Influence of sliding velocity on lubrication state of surface texturing

为了研究滑动速度对织构化摩擦副的润滑状态的影响,采用Nd：YAG固体脉冲激光对GCr15钢盘表面进行织构化处理,形成直径约150μm、深度约30~40μm的环形排列的微孔。在摩擦试验机上对Al_2O_3陶瓷球/GCr15钢盘进行摩擦学性能测试,并基于Stribeck曲线和弹流理论研究滑动速度对织构化表面润滑状态的影响。研究结果表明：在油润滑条件下,试样的摩擦因数随滑动速度的增大而减小。当滑动速度大于2 m/s,润滑状态从混合润滑逐渐进入到流体润滑区域;而经过织构化处理的配副能在较低的速度下实现由混合润滑向流体润滑状态过渡。根据磨损形貌比对可以看出：在流体润滑状态下,织构可以增加摩擦配副间的润滑膜厚度,使流体产生额外动压,提高油膜承载能力,减少磨痕宽度。

In order to study the influence of sliding velocity on the texturing of the lubrication state, the dimples with about 150 μm in diameter and 30-40 μm in depth arranged circularly were formed on GCr15 steel with Nd：YAG solid-state pulsed laser. The testing of tribological performance was investigated on the friction tester for Al_2O_3 ball/GCr15 disc and the influence of sliding velocity on lubrication state was analysed based on Stribeck curve and elasto-hydrodynamic lubrication. The results show that the friction coefficient is decreased with the increase sliding speed under the oil lubrication. When the sliding velocity is over 2 m/s, the lubrication state changes from the mixed lubrication to the fluid lubrication gradually, and the texturing pairs can be achieved at a low speed by mixed lubrication to fluid lubrication transition. According to the wear morphology comparison, the surface texturing can increase the lubricant film thickness to add the additional fluid dynamic pressure, increase the capacity of oil film and reduce the wear scar width in fluid lubrication.