ION-IMPLANTATION OF COBALT-TUNGSTEN CARBIDE TOOLS FOR MACHINING TITANIUM

Cobalt-base tungsten carbide cutting tools were implanted with Cl, F, Br, I, S, In, Ga and Sn to dose levels of 2 x 10(16) ions cm-2 to 5 x 10(17) ions cm-2. Both untreated and implanted tools were tested in turning against a log of Ti-6Al-4V alloy at a cutting speed of 300 f.p.m. Each test was carried out for 1 min and the uniform flank wear was measured, whereupon the tool was tested for a further 1 min. Testing continued in this fashion until the uniform flank wear approached or exceeded 0.02''. The distribution of the implanted elements was determined by secondary ion mass spectrometry. In general, doses of 1 x 10(17) ions cm-2 increased tool life by a factor of two in the case of the chlorine and indium implants. Other implant elements were less effective in increasing tool life against the titanium alloy.