热解石墨材料的载流磨损性能研究

Wear properties of pyrolytic graphite materials with electric current

采用交流串激式高速微电机对热解石墨材料进行载流磨损性能测试,重点研究在持续电弧作用下热解石墨材料的载流磨损特性;采用偏光显微镜、扫描电镜和透射电镜研究热解石墨材料磨损面的微结构变化。研究表明:电弧侵蚀是影响热解石墨材料的微结构变化的主要因素。在额定电压110V,热解石墨材料的载流磨损率最大,达6.2×10^(-6)mm^3·m^(-1)·N^(-1),摩擦副间的电火花高度最大,火花等级为2级;在加载电压为100V时,热解石墨材料的栽流磨损率相对最低,为0.9×10^(-6)mm^3·m^(-1)·N^(-1),且摩擦副间的电火花等级约为11/4级。研究还发现,载流磨损后热解石墨材料的磨损面上出现了明显氧化现象和电侵蚀痕迹,沿滑行方向存在大量杂乱分布的电弧侵蚀坑和表面开孔。热解石墨材料/铜合金的载流磨损机理主要是电侵蚀、氧化磨损以及不同程度的剥层磨损的交互作用。

Pyrolytic graphite material was measured on an AC series high-speed micro-motor, and Wear properties of pyrolytic graphite materials under arc erosion was studied systematically.The microstructure evolution of wear surface of pyrolytic graphite material was studied by polarized light microscope, scanning electron microscope and transmission electron microscope.The results show that the arc erosion is the dominant reason upon texture change of pyrolytic graphite material. At rated voltage of 110V, its wear rate with electric current is the highest, being 6.2×10-6mm3·m-1·N-1, as well as its corresponding electric spark, grade 2. When the condition of the rated voltage is 100V, the wear rate of pyrolytic graphite material is relatively low, being 0.9×10-6mm3·m-1·N-1, as well as its electric spark between the friction pairs, about grade 11/4. Furthermore, there were obvious oxidation phenomenon and electric erosion trace on the wear surface with electric current of pyrolytic graphite material, and there were a lot of random electric erosion pits and open-holes along the sliding direction. The main wear mechanism with electric current of pyrolytic graphite/copper alloy is the interaction of arc erosion, oxidation wear and different degrees of delamination wear.