沟槽形表面织构对摩擦噪声的影响

Effects of Grooved Surface Texture on Friction Noise

用电加工方法在制动盘蠕墨铸铁材料表面加工出沟槽形表面织构(沟槽深度为30μm、宽度为150μm、间距为500μm),采用球—平面接触方式,选取直径为10mm的Si3N4球为对磨副,对沟槽形织构表面和光滑表面进行了摩擦噪声对比试验,研究了沟槽形表面织构对界面摩擦振动噪声的影响。试验结果表明(以下结论只针对本试验选定尺寸规格的沟槽形表面织构):法向载荷对织构表面产生摩擦噪声强度的影响较小,而对光滑表面产生摩擦噪声的水平具有重要影响;沟槽形织构表面在低法向载荷下较光滑表面更易产生摩擦噪声,但随着法向载荷从5N增大到10N,光滑表面产生的摩擦噪声强度迅速增大并与织构表面的接近;沟槽形表面织构使摩擦系统更易产生多频率的摩擦振动,较早地产生摩擦噪声且其主频率成分较复杂;沟槽形织构表面比光滑表面具有较高的摩擦因数和耐磨性,沟槽形织构的存在明显地改变了接触界面摩擦磨损行为和摩擦噪声特性,但其对应关系需要进一步深入研究。

Grooved surface texture was manufactured on the surface of compacted graphite iron samples（brake disc material）by electromachining,with the grooves of 30μm in depth,150μm in width and 500μm in pitch.Comparative friction noise tests between groove-textured and smooth surfaces were performed in a ball-on-flat configuration by using Si3N4ball with diameter of 10mm as counterpart and the influence of grooved surface texture on friction noise was investigated.The test results（applicable only to the grooved surface texture adopted herein）show that the normal load has little influence on the friction noise level of the groove-textured surface,but significant influence on that of the smooth surface.Friction noise has a greater tendency to be generated at the groove-textured surface under low normal load.However,friction noise generated at the smooth surface increases its level rapidly approaching to that of the groove-textured surface,as the normal load increases from 5Nto 10N.The grooved surface texture makes the friction system easier to generate multi-frequency friction vibration,and thus earlier friction noise with more dominant frequency components.The groovetextured surface has higher coefficient of friction and wear resistance as compared to the smooth surface.The existence of surface texture does change the fiction and wear behaviors as well as friction noise properties of the frictional surfaces,but their corresponding relationship requires further study.