(昆明理工大学 机电工程学院，昆明 650500)
摘 要: 采用纳米压痕仪对单晶锗进行变载荷纳米划痕实验和恒定载荷纳米划痕实验，分析不同划痕速度和不同载荷对单晶锗切削特性的影响规律；采用原子力显微镜对样品表面进行扫描观测，分析单晶锗微纳米尺度切削加工的材料去除机理。研究结果表明：划痕速度分别为10、20和50 μm/s时，单晶锗(100)晶面脆塑转变临界切削力分别为10.2、12.1和9.8 mN，呈现先增大后减少的规律；单晶锗(110)晶面脆塑转变临界切削力分别为9.5、7.7 和6.9 mN，呈现随着划痕速度的增大而减少的规律；单晶锗(111)晶面脆塑转变临界切削力分别为8.3、8.5和8.9 mN，划痕速度的改变对于切削力的变化基本没有影响；当载荷分别为10、30和50 mN时，单晶锗(110)晶面切削力分别为0.3、4.5和12.5 mN。随着划痕速度的增大，单晶锗不同晶面切削特性表现出明显的各向异性；随着载荷的增大，单晶锗切削力也相应增大，切削力的波动范围也越来越大。本研究为分析单晶锗微纳米尺度塑性域切削提供理论基础和数据支持。
关键字: 单晶锗；微纳米尺度；变载荷纳米划痕实验；恒定载荷纳米划痕实验；切削特性；切削力
（Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming 650500, China）
Abstract:The variable load and constant load nano-scratch experiments of single crystal germanium were carried out by using nano-indentation apparatus. The effects of different scratch speeds and different loads on the cutting characteristics of single crystal germanium were analyzed. The surface of the sample was scanned by atomic force microscopy and the material removal mechanism of micro-nano-scale cutting of single crystal germanium was investigated. The results show that when the scratch speeds are 10, 20 and 50 μm/s, the critical cutting forces of the brittle-ductility transition of Ge(100) surface are 10.2, 12.1 and 9.8 mN respectively, showing a pattern of increasing first and then decreasing. The critical cutting forces of Ge(110) crystal surface are 9.5, 7.7 and 6.9 mN, presenting a regularity that the critical cutting force decreases as the scratch speed increases. The critical cutting forces of Ge(111) are 8.3, 8.5 and 8.9 mN, showing that the alteration of the scratch speed has no effect on the change of the cutting force. Moreover, when the loads are 10, 30 and 50 mN, the cutting forces of Ge(110) are 0.3, 4.5 and 12.5 mN, respectively. Therefore, with the increase of scratching speed, the cutting behavior of single crystal germanium shows obvious anisotropy. As the load increases, the cutting force of the single crystal germanium augments accordingly, and the fluctuation range of the cutting force becomes larger and larger, which provides data support for the analysis of the micro-nano-scale plastic domain cutting of single crystal germanium.
Key words: single crystal germanium; micro-nano-scale; variable load nano-scratch test; constant load nano-scratch test; cutting characteristics; cutting force
