Design, optimization and manufacturing of polycrystalline diamond micro-end-mill for micro-milling of GH4169

Abstract

Diamond micro mills are very suitable to process the nickel-based superalloy GH4169 because of its high stiffness and edge sharpness. The geometric parameters of micro-end-mills have a significant effect on the milling process. In order to determine the optimal tool geometric parameters, a micro-end-mill was designed and used to simulate the micro-milling of GH4169 with a three dimensional (3D) finite element method (FEM). Subsequently, micro-milling verification experiments were performed. In the simulation, the maximum tension stress of the tool (MTST), the range of cutting force fluctuation (RCFF), and the residual stress of the machined surface (RSMS) were defined as indicators of parameters optimization. The obtained optimal tool parameters were: rake angle of 0°, relief angle of 9°, and cutting-edge radius of 1–1.5 μm. Moreover, the above optimal parameters were used to manufacture a micro-end-mill of polycrystalline diamond (PCD) through the precision grinding method assisted by laser-induced graphitization. Cutting experiments using commercial and PCD tools demonstrated that the PCD micro-mill has better cutting performance than a commercial cemented carbide micro-mill.