Development of Tool Wear Standards and Wear Mechanism for Micro Milling Ti-6Al-4V Alloy

Abstract

With the rapid development of high-precision-device technology, new demands are put forward for micro milling. The size effect and low cutting energy of micro milling make the process expensive and difficult, especially for Ti-6Al-4V alloys. The wear of the micro-milling cutter lacks corresponding international standards and its cutting mechanism is complex. In this paper, four kinds of micro-milling cutters with different wear states were obtained by designing micro-milling experiments, and the wear process and wear mechanism were observed and analyzed. The cutter diameter reduction, end face wear, flank wear and edge radius are comprehensively analyzed. It is considered that the formulation of a micro-milling-cutter wear standard needs comprehensive consideration, and the wear of end face 30 μm, wear of flank 35 μm and tool diameter reduction 55 μm can be used as the failure criteria of the micro-milling cutter. The wear forms mainly include abrasion marks, material adhesion, built-up edges and micro-collapse blades. Adhesive wear exists in the whole cutting process and plays a major role. Abrasive wear, diffusion wear and oxidation wear will occur when the cutting temperature reaches the melting point of Co. The wear of the micro-milling cutter is analyzed more comprehensively, a new wear-failure standard is formulated and the complex wear mechanism is revealed.