Improvement of mechanical properties and application for cutting tools of TiB₂-base thin films

Abstract

TiB₂ base thin films have been prepared by DC magnetron sputtering with a sintered TiB₂+B target to obtain high cutting performance against stainless steel used as an airplane material. The critical loads (adhesive strength) and microhardness of TiB_2+α films were higher than those of TiB₂ films. The TiB_2+α-based Ti-B-C films with C content of about 50% had good frictional properties compared to TiB_2+α film, and the friction coefficients decreased from 0.8 to 0.4. Cemented tungsten carbide cutting tools were coated with Ti-B-C film with high adhesive strength, high hardness, and low frictional properties. Chips formed with the Ti-B-C coated tool were smoother than those formed with uncoated tools.