Evaluation and quantification of diffusion wear between cutting chip and workpiece using forging press

Abstract

The state of the interface between the workpiece and the cutting tool affects the cutting temperature and pressure on the tool surface during the cutting process. In particular, while cutting difficult-to-cut materials such as Ni-based alloy 718, the workpiece exhibits a high affinity for cutting tool materials and could easily adhere to them. Adhesion can, at times, adversely affect productivity. The diffusion between the cutting tool and the workpiece is a factor considered to contribute to the adhesion phenomenon during cutting. Addressing this issue involves choosing tool materials and coated materials with high resistance to diffusion and optimizing cutting conditions, particularly the cutting speed, which significantly impacts cutting temperature. However, because cutting tool wear comprises various forms, clarifying the effect of diffusion on tool wear remains open. In this study, to reproduce the diffusion phenomenon between cutting tool and workpiece, two pairs of test specimens were prepared: (1) cemented carbide-AISI 1045 and (2) cemented carbide-Alloy718, which could be held at high temperature under vacuum conditions by a forging press. The degree of diffusion phenomena was evaluated at each tool-work material interface, and the quantification of diffusion amount was performed by diffused element in each work material. Additionally, the theoretical analysis of the diffusion phenomenon using the thermodynamic and phase diagram calculation software Thermo-Calc was also performed.