Study on grinding surface quality of superalloy GH4145

Abstract

Nickl-based Superalloy GH4145 is widely used in aero-engine springs, blades, and other parts due to its excellent mechanical properties. It is a high-hardness and difficult-to-machine material. Improving the surface quality after processing has great significance for the long-term stable service of aero-engines. In this paper, Simulation models with different rake angles were established to predict the damage forms on the machined surface and subsurface on Abaqus. The effects of different process parameters on the surface quality of GH4145 were studied by using CBN grinding wheel. The influence of experimental parameters on the surface quality of GH4145 was analyzed and the related grinding mechanism was expounded. Under the scanning electron microscope (SEM) detection, the crack propagation process and the phenomenon of serious damage to the surface quality such as white layer were analyzed. The results show that the single particle prediction models with different rake angles can reflect the actual grinding situation to a large extent, and the model with the rake angle of -15° is more consistent with the detection phenomenon observed in this experiment. The surface damage forms are mainly pits, burrs, and boundary bosses caused by plastic deformation under simulation and experimental detection. The detection of the subsurface shows that in addition to the above phenomena, there are cracks and debris adhesion. The linear velocity of the grinding wheel is the main factor affecting the surface quality of the machined surface, the cutting depth is the second, and the feed rate has the least influence. The maximum roughness in the grinding experiment reaches 1.992 µm. Considering the thermal softening phenomenon of the material, the linear velocity range should be selected from 30 m/s to 35 m/s, and the feed rate and grinding depth should be selected relatively small values.