(大連交通大學(xué) 軌道交通關(guān)鍵材料實(shí)驗(yàn)室，大連 116028)
摘 要: 采用粉末冶金技術(shù)制備銅−石墨−SiO2燒結(jié)材料，利用銷盤式摩擦試驗(yàn)機(jī)，在摩擦速度為7.8~47.1 m/s的范圍內(nèi)，研究SiO2在不同摩擦速度條件下的損傷機(jī)理及其與材料性能的關(guān)系。結(jié)果表明：SiO2對材料摩擦磨損性能的影響與摩擦速度密切相關(guān)；低摩擦速度條件下，SiO2含量的變化對提高摩擦因數(shù)的作用明顯，原因在于摩擦力的靜載荷性質(zhì)有利于發(fā)揮SiO2粒子的犁溝作用而增加摩擦力；材料的磨損率對SiO2含量不敏感；高摩擦速度條件下，具有沖擊作用的摩擦載荷導(dǎo)致SiO2粒子粉碎性破碎，破碎的SiO2粒子彌散嵌入高溫軟化的基體中而弱化了犁溝作用，導(dǎo)致摩擦因數(shù)對SiO2含量的變化不敏感；彌散分布的SiO2粒子強(qiáng)化基體表面強(qiáng)度，導(dǎo)致其磨損率隨SiO2含量的增加而降低。
關(guān)鍵字: 銅基摩擦材料；SiO2；摩擦行為；第三體
Cu-matrix friction materials
（Key Materials Laboratory for Railway, Dalian Jiaotong University, Dalian 116028, China）
Abstract:To investigate the relationship between dandification mechanism of SiO2 particles and materials performance under different friction speeds, Cu-graphite-SiO2 sintered materials were prepared through powder metallurgy. The tests were conducted on a pin-on-disk tester in speed range of 7.8−47.1 m/s. The results demonstrate that the effects of SiO2 on the friction and wear performance of the materials are closely related to the friction speed. At low friction speed, the friction coefficient increases with increasing content of SiO2 particles, this is attributed to the effect of SiO2 scratch, which can improve the friction force remarkably under static load. However, the wear rate is not sensitive to the content of SiO2 particles. At high friction speed, the SiO2 particles are broken by impact action and embedded in the matrix softened at high temperature, which results in reduction of scratch influence, and makes the friction coefficient insensitive to SiO2 content. The increase of surface hardness causes the wear rate to fall with increasing content of SiO2 particles.
Key words: Cu-matrix friction material; SiO2; tribological behavior; third body
