Study on the friction noise behaviour of coating textured surface based on STFT time-frequency analysis

The friction noise existing in the machining system will affect the stability and accuracy of the system, and the coating and micro-texture technology provides a solution to this problem. In this paper, orthogonal experiments are designed based on coating and micro-texture parameters, and a pin-disk friction and wear experimental platform is built. STFT is used to analyse the time-frequency of friction noise signals. The results show that the coating micro-texture can suppress the high frequency part of the noise. The process of coating micro-texture can be divided into three stages: the initial running-in stage, the validity period of coating micro-texture, and the coating micro-texture failure period. Taking the minimum decibel value of noise as the evaluation index, it is found that laser scanning speed, scanning times and p * d (interaction between laser power and micro-texture diameter) are the main factors affecting friction noise, and the micro-texture parameters of the coating are optimised: coating thickness 3 mu m, laser power 35 W, laser scanning speed 1,700 mm/s, laser scanning times 6, micro-texture diameter 60 mu m, and micro-texture spacing 130 mu m. It provides a theoretical and data basis for improving the interfacial friction performance.