This paper reports the properties of coatings of TiN on surfaces of high speed steel drills with hole cathode (HCD) and
nulti-arc
ion planting (MAI) techniques respectively.The
divided pressure of N 2 was 0.4 Pa for HCD,and 0.4 Pa,0.1 Pa,0.05 Pa for MAI. We compared the colors and microhardness of the coatings for different pressure of N 2. And also,observed the surface topography and cross-section images with the scanning delctronic microscope (SEM),and detected the thickness of layers. The bonding intensity between layers and substrates was measured by the way of scratching mark.The results of experiments indicates that the hardness of the coatings is 2～4 times higher than that of the substrates.The topography of different coatings for the two techniques and different pressures isn't the same.There are particles of 5～10μm size on the coation of MAI.From the SEM pictures, the images of the cross-section the coatings the coatings looks like layer by layer.The bonding intensity is getting higher as the divided pressure of N 2 increasing.