TITANIUM NITRIDE DEPOSITION ON HARDENED HIGH-SPEED STEEL BY REACTIVE MAGNETRON SPUTTERING

Hardened W-Mo-Co high speed steel SIS-2723 (Swedish standard) used for the manufacture of cutting tools was deposited with titanium nitride by reactive magnetron sputtering. In this work we have studied the influence of the substrate deposition temperature on the chemical composition, hardness and adhesion at the interface and in the bulk of the TiN film. At an approximately 400°C deposition temperature the critical load CL is at maximum. At the TiN film-substrate interface and at a 400°C deposition temperature it was also found that the ratios Si:N, C:N, C:Ti, Mo:N and Cr:N are at maxima and N:Ti is at a minimum. At a 200°C deposition temperature the O:Fe ratio at the interface is at a maximum and between 400 and 500°C this ratio is at a minimum. The titanium nitride surface hardness as well as the ultramicrohardness in cross-section reach maxima at a 400°C deposition temperature. Further analysis of the TiN film adhesion shows that it is adhesive at deposition temperatures below 350°C and cohesive at higher temperatures. © 1990.