Effects of Cutting Speed on the Wear Properties of TiAlN PVD Coated Tool for Cutting P20 Mold Steel

Abstract

High-speed cutting is an important method for improving the efficiency and quality of machining mold steel, but the wear of tool is one of the key factors restricting the improvement of cutting speed, which brings higher requirement for the material of tools. At present, most of the research is about high-speed cutting for high hardness mold steel, while only a limited research work on the pre-hardened plastic mold steel with hardness between 30 HRC and 42HRC, such as P20 mold steel. To explore the effects of cutting speed on the wear properties of TiAlN PVD coated tool for cutting P20 mold steel, the experiments in different cutting speeds were carried out under dry condition. Wear characterization of the rake and the flank surfaces were investigated by using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). It was revealed that at the low speed (160m/min), adhesion (built-up edge) followed by delamination was found to be the cause of wear damage; at the high speed (320m/min), the dominant wear mechanisms were oxidation wear and diffusion wear, followed by adhesive wear and melt wear; as the cutting speed increased, the proportion of oxidation wear and diffusion wear was gradually increased.