Yin Shenxin, Xiao Huapan, Kang Wenjun, Wu Heng, Liang Rongguang
College of Aerospace Engineering, Chongqing University, Chongqing 400044, China.
College of Mechanical and Vehicle Engineering, Chongqing University, Chongqing 400044, China.
Materials (Basel). 2021 Dec 29;15(1):233. doi: 10.3390/ma15010233.
The damaging of ZnSe crystal has a significant impact on its service performance and life. Based on the specific cutting energies for brittle and ductile mode machining, a model is proposed to evaluate the damage depth in the shoulder region of ZnSe crystal during single point diamond machining. The model considers the brittle-ductile transition and spring back of ZnSe crystal. To verify the model, the elastic modulus, hardness, spring back, and friction coefficient of ZnSe crystal are measured by nanoindentation and nanoscratch tests, and its critical undeformed chip thickness is obtained by spiral scratching. Meanwhile, orthogonal cutting experiments are conducted to obtain the different shoulder regions and cutting surfaces. The shoulder damage depth is analyzed, indicating that the effect of the feed on the damage depth at a high cutting depth is stronger than that at a low one. The model is verified to be effective with an average relative error of less than 7%. Then, the model is used to calculate the critical processing parameters and achieve a smooth ZnSe surface with a roughness Sa = 1.0 nm. The model is also extended to efficiently predict the bound of the subsurface damage depth of a cutting surface. The research would be useful for the evaluation of surface and subsurface damages during the ultra-precision machining of ZnSe crystal.
ZnSe晶体的损伤对其使用性能和寿命有重大影响。基于脆性和延性模式加工的特定切削能量，提出了一个模型来评估单点金刚石加工过程中ZnSe晶体肩部区域的损伤深度。该模型考虑了ZnSe晶体的脆-延性转变和回弹。为了验证该模型，通过纳米压痕和纳米划痕试验测量了ZnSe晶体的弹性模量、硬度、回弹和摩擦系数，并通过螺旋划痕获得了其临界未变形切屑厚度。同时，进行了正交切削实验以获得不同的肩部区域和切削表面。对肩部损伤深度进行了分析，结果表明，在高切削深度下进给量对损伤深度的影响比在低切削深度下更强。验证该模型有效，平均相对误差小于7%。然后，使用该模型计算临界加工参数，并获得粗糙度Sa = 1.0 nm的光滑ZnSe表面。该模型还被扩展以有效地预测切削表面的亚表面损伤深度范围。该研究对于评估ZnSe晶体超精密加工过程中的表面和亚表面损伤具有重要意义。
