Study on High Speed Cutting of Bio-Titanium alloy

Abstract

Using a binder-less PcBN tool, the influences of cutting speed on tool life and wear pattern in turning of Ti-6Al-2Nb-1Ta, which was a vanadium free titanium alloy for a surgical implant material, were investigated. In the condition of feed rate of 0.15mm/rev and depth of cut of 0.5mm with an application of a high pressure coolant, the tool life at cutting speed of 4.2m/s was the longest in the various cutting speeds. In conditions of cutting speed of below 4.2m/s the tool life was determined by chipping and flaking occurring on tool face, on the other hand, smooth wear on the tool face were observed in over 4.2m/s. And, it was confirmed that the smooth wear on the tool face in turning process appeared over 730°C of tool flank temperature , and the promotion of tool wear was so dependent on the cutting temperature. Also, in order to investigate this reaction in the cutting process, the experimental model reaction test between the tool material and the workpiece one by using the SPS equipment were conducted in addition to element analysis of the adhesive on the cutting edge using EDS and XRD. As a result, it was clarified that TiB2 was generated in the interface between the binder-less PcBN and the titanium alloy, and the reaction was sensitive to its temperature.