接触压力与粉末层厚度对塑性拉延过程的影响  

Influence of contact pressure and thickness of powder layer on powder lubrication in metal plastic forming

作　　者：史超[1] 王伟[1] 刘焜[1] 

机构地区：[1]合肥工业大学摩擦学研究所,安徽合肥230009

出　　处：《合肥工业大学学报（自然科学版）》2016年第12期1608-1613,共6页Journal of Hefei University of Technology：Natural Science

基　　金：国家自然科学基金资助项目(51175136;51475135);中国博士后科学基金资助项目(2014M550339);清华大学摩擦学国家重点实验室开放基金资助项目(SKLTKF13A2)

摘　　要：文章以石墨粉末作为固体润滑剂,在不同接触压力和粉末层厚度下,对铝合金进行了一系列塑性拉延摩擦试验,得到了铝合金在粉末润滑条件下的摩擦系数和表面膜特性,并对塑性成形过程粉末润滑机理进行了分析。结果表明:爬行现象是润滑膜破坏的主要原因,该现象随着接触压力的增大而加剧;适当增加粉末层厚度可以有效降低润滑膜的损伤,但不是粉末量越多越好,最佳厚度随使用工况而变化;不同粉末层厚度下,表面膜的典型破坏形式有所区别;摩擦系数随着接触压力的增加而减小,随着粉末层厚度的增加而增加。By using graphite powder to lubricate the sliding contact interface during strip drawing, the friction tests on the aluminum alloy were performed under different contact pressures and with differ- ent thickness of powder layer. The friction coefficient and the characteristics of surface film of the alu- minum alloy were measured during or after experiments. The mechanism of particle flow lubrication in sheet metal forming was also studied. The results indicate that the surface film is mainly damaged by crawl phenomenon which is intensified with the increase of contact pressure. To increase the thick- ness of the powder layer appropriately can reduce the damage of the lubricant film, but too much graphite does not mean better, the optimum thickness varies with the change of operation condition. The typical damage behavior of the surface film changes with different thickness of powder layer. The friction coefficient deceases with the increase of contact pressure and increases with the increase of the thickness of powder layer.

关 键 词：塑性成形 石墨 润滑 摩擦学 爬行现象 

分 类 号：TH117.1[机械工程—机械设计及理论]