沟槽型织构化表面摩擦噪声特性试验研究

用电火花加工方法在制动盘蠕墨铸铁材料表面加工出不同沟槽宽度和间距的沟槽型表面织构,在自行研制的新型摩擦噪声试验装置上,采用球-平面接触方式,选取直径10 mm的GCr15球为对摩副,对沟槽型织构表面和光滑表面进行摩擦噪声对比试验,研究沟槽型织构对摩擦噪声的影响.结果表明:本试验条件下沟槽型表面织构的尺寸及分布对摩擦噪声具有重要影响,一定尺寸及分布的织构表面可明显降低摩擦噪声.本试验条件下的摩擦噪声产生主要归因于接触表面的不平顺、磨屑层不均匀分布以及犁削作用等界面因素,这些因素导致了界面摩擦力高频成分的产生,当其与系统的自然频率耦合时,将引起摩擦系统强烈的自激振动并最终产生摩擦噪声.而摩擦界面存在尺寸分布合理的沟槽型表面织构,将能提高界面排屑能力并打断摩擦界面连续的接触,扰乱摩擦系统的自激振动,抑制摩擦噪声的产生.

An Experimental Study on Friction Noise Properties of Groove-Textured Surfaces

Grooved surface texture with different widths and pitches were manufactured on the surfaces of compacted graphite iron samples (brake disc material) by electro-machining. The influence of grooved surface texture on friction noise and the difference between the groove-textured and original smooth surfaces in friction noise properties were studied in a ball-on-flat configuration, by using a new-developed friction noise experimental apparatus. A 10 mm diameter GCr15 ball was used as counterpart. The test results show that the width and pitch of the grooved surface texture had a significant influence on the friction noise properties, some groove-textured surfaces with specific width and pitch can reduce friction noise. In this work, the generation of friction noise can be mainly attributed to the irregularity of the contact surface, uneven distribution of the debris layer and plowing, which caused the high frequency components of the interface friction force. Friction noise can be generated when those high frequency components coupled with the natural frequency of system and caused strong self-excited vibration. In contrast, grooved surface texture with specific width and pitch helped to remove the wear debris from the contact surfaces and interrupt the continuous contact of the friction interfaces, which disrupted the self-excited vibration of the friction system and finally reduced the generation of friction noise.