Investigations on chip formation of turned novel AM alloy

Abstract

Manufacturers across varied segments look for materials having appreciable machinability and surface integrities. Machinability of Mg alloys is a vital aspect during their acceptance for different applications. The chip shape generated in the cutting operation is a crucial attribute dominating the surface roughness, besides the dimension’s precision and the tool lifespan. The study discusses the chip-formation through the dry turning of a novel AM alloy (Mg alloy with 7 wt%Al-0.9 wt%Mn) using carbide insert with a 0.4 mm nose radius. During the experiments, three chip dimensions, namely chip-thickness, chip-length, and chip-width were measured. The turning variables, namely cutting speed( v), depth of cut (DOC), and feed ( f) is altered and applied to the workpiece. The chip shape was mostly dependent on the grouping of turning parameters. It was seen that favorable continuous chip formed at high feed and low DOC. The % contribution of each turning parameter on the chip shape was calculated. The experimental results are validated with the help of analysis of variance (ANOVA). The results show that the % contribution of feed, speed, and DOC on chip-thickness is 58.49%, 28.91%, and 12.49%; the contribution on chip-length is 76.89%, 20.81%, and 2.23%; and on chip-width, it is 25.28%, 0.48%, and 74.33%, respectively. Further, the chip shapes were compared with the shapes that were predicted by FEM software. The study offers vital insights for parameter selection to improve chip shape, which, in turn, contributes to higher surface quality.