Cutting force and tool wear in cutting Ti-6Al-4V using microstructure-based PCD turning tools

Abstract

Titanium and its alloys have been widely applied in surgical, aerospace, and medicine because of its high corrosion resistance, strength, heat resistance, and high compatibility with composite structures. However, due to the small cutting deformation coefficient and severe cold hardening phenomenon of titanium alloy, high stress and temperature can easily occur near the cutting edge during machining, which caused chips to adhere to the surface of tools and accelerated tool wear. In order to reduce cutting force and tool wear, researchers have attempted to fabricate microstructures on the tool by grinding, lithography, etching, and other technologies to improve lubrication condition between tools and chips. However, these processes were limited to certain conditions. In this paper, three-dimensional (3D) laminated microelectrodes were used to fabricate various microstructures on polycrystalline diamond (PCD) turning tools by micro-electrical discharge machining (micro-EDM). Moreover, microstructure-based PCD turning tools were used to perform cutting experiments on titanium alloy. During this process, the cutting force of PCD turning tools were measured by force measuring device, and chips were collected and observed. After that, the friction coefficient and tool wear of PCD tools with different microstructures were measured. The experimental results show that microstructures on the rake face of PCD turning tools can effectively reduce friction coefficient for cutting titanium alloy, thus reducing cutting force and tool wear. The type and size of microstructures also affect cutting force and tool wear: the smaller size of microstructure, the smaller values of cutting force and tool wear.