Grinding surface and subsurface stress load of nickel-based single crystal superalloy DD5

Abstract

Nickel-based single crystal superalloys have broad application prospects in the aerospace field. Their excellent physical properties enable the workpiece to serve in complex environments for a long time, and are often used in the most complex stress and the worst working conditions. However, the damage caused by mechanical material removal deteriorates the wafer surface flatness and die strength, while its surface and subsurface formation principle has yet to be revealed. This study aims to analyze the influence of abrasive particles on the load of the workpiece during machining was scrutinized through the lens of stress tensor, yield performance, and third invariant. The results indicate that, a substantial stress load is exerted on the front end of the abrasive grain, leading to the yield deformation of the workpiece. Conversely, the stress load at the bottom of the abrasive grain is comparatively lower, resulting in tensile deformation and the formation of a discernible plastic damage layer. To delve deeper into the workpiece's damage phenomenon, this study conducts a comparative analysis from the standpoints of chips, surface morphology, and subsurface characteristics of DD5. Experimental results indicate that the chips on the contact surface exhibits a relatively smooth texture, while the grinding surface manifests grooves of varying depths. Concurrently, subsurface analysis reveals the presence of slip deformation and elemental flow. This investigation elucidates the intricate interplay between the grinding process and subsurface loading, offering valuable insights to enhance the quality and precision of nickel-based single-crystal superalloy workpiece manufacturing.