镍基单晶高温合金磨削表面质量及亚表面微观组织试验

采用正交试验的方法，研究了镍基单晶高温合金DD5表面质量影响因素和亚表面微观组织.进行DD5平面槽磨削正交试验，得到砂轮线速度、磨削深度和进给速度对表面质量的影响规律，优选出最优工艺参数组合，并对磨削亚表面微观组织和磨屑形貌进行观察.结果表明:砂轮线速度对磨削表面粗糙度R_○a影响最大;随着砂轮线速度的增大，表面粗糙度R_○a不断减小;随着磨削深度和进给速度的增大，表面粗糙度R_○a不断增大.选出的镍基单晶高温合金DD5平面磨削试验参数范围内的最优工艺参数组合:砂轮线速度为30m/s，磨削深度为20μm，进给速度为0.2m/min.磨削亚表面出现了塑性变形层和加工硬化层.磨屑主要呈现出一节一节的锯齿状特征.

Experiment of Grinding Surface Quality and Subsurface Microstructure for Nickel-Based Single Crystal Superalloy

The orthogonal experiments were conducted to carry out the research of surface quality influential factors for nickel-based single crystal superalloy DD5 and subsurface microstructure in grinding. The orthogonal experiment of DD5 plane slot grinding was conducted. The influence of grinding wheel linear speed， grinding depth and feed rate on grinding surface quality was concluded， and the optimized parameters combination was also selected. The grinding subsurface microstructure and debris morphology were observed then. The results show that: the grinding wheel linear speed has the greatest influence on the grinding surface roughness R_○a; with the increase of grinding wheel linear speed， the grinding surface roughness R_a decreases;with the increase of grinding depth and feed rate， the grinding surface roughness R_a increases. The optimized parameters combination of nickel-based single crystal superalloy DD5 within the experimental parameters in plane grinding is as the following: grinding wheel linear speed is 30m/s， grinding depth is 20μm and feed rate is 0.2m/min. The plastic deformation layer and the machined hardening layer appear on the grinding subsurface. The grinding debris mainly presents the serrated features.