极薄车削中切屑形貌的实验分析

Experimental Analysis of Chip Geometry in Ultraprecision Tarning

采用圆弧刃金刚石车刀对铝和单晶锗进行超精密车削实验，对切屑在扫描电子显微镜下进行观察。当切削厚度达到纳米级时，得到了和常规切削同样的由剪切滑移的层状薄片堆积形成的连续带状切屑。但是切屑的变形系数远远大于常规切削下的切屑变形系数，一般可达２０以上。对实验结果的分析说明对单晶锗实现了最小切削厚度为２０ｎｍ的稳定切削。

In this paper, the ultraprecision turning of aluminum and single crystal germanium were carried out with the round edge diamond tools, and the chip geometry were observed with scanning electron microscope(SEM). Observation shows that the stable shear-banded chip can be removed even at nanometric thickness of cut, but the chip deformation coefficient can achieve above 20, much more than that obtained in the conventional machining. The analysis of experiment results shows that the minimum thickness of cut of 20nm was stably carried out in the microcutting of single crystal germanium。