High Speed Machining of Bio-Titanium Alloy with a Binder-Less PcBN Tool

Using a binder-less PcBN tool, improvement of processing efficiency was tried in machining of a vanadium-free titanium alloy, Ti-6Al-2Nb-1Ta which was recently applied for a surgical implant material. The tool which is prepared through the direct conversion sintering of h-BN under both high pressure and temperature, exhibits an improved high thermal durability. It was confirmed that a binder-less PcBN tool exhibited lower flank wear and kept sharper cutting edge compared to the tools made of materials such as sintered carbide, conventional PcBN and polycrystalline diamond with Co-based binder, after turning in cutting speed of 4.2m/s, feed rate of 0.15mm/rev, depth of cut of 0.5mm under an application of a high pressure coolant. Also, milling tests were conducted with a radius end mill tool whose tip was made of the binder-less PcBN material. As a result, the possibility of high speed milling at cutting speed of 8.3m/s was found.