Study on the chip formation in grinding of nickel-based single-crystal superalloy DD5

According to the significant anisotropy of nickel-based single-crystal superalloy, a three-dimensional single-abrasive grinding model based on the Hill model was developed. In work, the change of the actual grinding thickness (ag) of abrasive is taken into account in establishing the model. In addition, a combination of theoretical research and experimental research is used. The surface morphology and chip morphology of DD5 were first studied. Then, the chip morphology evolution and the grinding force change were investigated. Finally, the influence of grinding speed (vs) on chip morphology and chip segmentation frequency (fc) was studied. The research shows that serrated chips can easily occur when machining DD5 within the range of grinding parameters. The grinding force increased steadily and was accompanied by inevitable periodic fluctuations corresponding to serrated chips. As the grinding speed increased, the abrasive could enter the cutting stage more quickly, and their critical chip thickness (acr) eventually decreased from 0.225 to 0.158 μm, and the percentage of the cutting phase increased from 85 to 89.5%. The critical scratch thickness, on the other hand, was not significantly influenced by the change in grinding speed. The grinding speed and thickness substantially influence the morphology and segmentation frequency of DD5 chips. Specifically, when grinding speed continues to increase, the DD5 chip morphology changed from a densely stacked unit nodal shape with serrated subsections to a continuous type of serrated shape and finally developed into a strip-shaped chip. At different grinding speeds, the chip segmentation frequency of DD5 decreases with increasing grinding depth.