Abstract: 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.

Key words: nickel-based single crystal superalloy DD5, grinding, surface quality, orthogonal experiment, subsurface, grinding debris