磨料粒度对表面微织构纯钛干摩擦性能的影响

Effect of Wear Particle Size on Dry Tribological Properties of Surface Texturing Titanium

为了提高钛及钛合金钻具在超深钻探、深海钻探和外太空钻探工程中的减摩抗磨性能。利用激光表面加工技术在工业纯钛(TA2)表面制备了不同参数的点阵微织构。采用MS-T3000摩擦磨损试验机测试了微织构钛合金在不同粒度模拟月壤作用下的摩擦学性能。利用扫描电子显微镜和能谱分析仪分析磨痕形貌及元素含量。研究结果表明:当磨料粒度小于微织构点阵的直径时,磨料压入微织构点阵里,磨料具有滚动和滑动两种运动方式。当粒度大于微织构点阵的直径时,磨料不能完全压入微织构点阵里,磨料对微织构TA2表面产生了滑动犁削作用。由于两种磨料磨损的作用机理不同,同等条件下,小粒度的磨料作用下的微织构TA2的摩擦因数和磨损率较大粒度磨粒作用下的最大减少量分别为50%和53%。考虑磨料粒度与微结构的匹配性,可以大大降低摩擦减少磨损。

In order to improve anti-friction and anti-wear performance of the titanium alloy drilling tools used in the ultra deep drilling, deep sea drilling, and drilling engineering in outer space. Dimple textures are prepared on TA2 titanium surface by means of laser surface texturing(LST). Tribological behaviors of the texturing surfaces are investigated under lubrication with two kinds of simulated lunar soil in dry sliding contact on a MS-T3000 friction and wear tester. The micro-morphologies and element content on the worn surfaces are analyzed by scanning electron microscopy(SEM) and energy dispersive spectrometer(EDS), respectively. The result shows that the wear particle would be compressed to completely embed into the dimples while lubricated by small particles. The small wear particles combine with rolling and sliding movements in the process of sliding which lead to lower friction and wear on the texturing TA2 surface. However, unavoidable sliding damages take place the texturing surface lubricated by large particles. The large foreign particles are too difficult to be squeezed to embed completely into the dimples results in larger friction coefficients and wear rate on the texturing TA2 surface. So, the highest reduction ratios for friction coefficient and wear rate are 50% and 53% for the texturing surface which is lubricated by small particles comparing with it lubricated by large particles. Besides, the matching rate of abrasive particle size and texture parameter can greatly reduce friction and wear.