HARDNESS AND ADHESIVE PROPERTIES OF (CR, MO) OXYCARBIDE FILMS ON STAINLESS-STEEL VIA VAPOR-DEPOSITION

A hexacarbonyl of chromium and molybdenum [(Cr, Mo)(CO)(6)] was used a s an oxycarbide source for the coating on stainless steel 304 (SS304) at temperatures from 175 degrees C to 450 degrees C. Hardness of the f ilms was determined from a microindentation technique through a simila r calculation after Thomas (1987). Intrinsic hardnesses of the films f ormed at low and medium temperatures were determined to be 8.61 and 2. 75 Cpa, respectively. Both of them are larger than that of SS304 subst rate, 1.75 Cpa. Adhesive strength of the films was measured by the scr atching test. The results reveal that the adhesive strengths of the fi lms formed at low, medium, and high temperatures are 2.8 N, 37.6 N, an d 36.0 N, respectively. Two different fracture modes after scratching were found for the films obtained at various temperature regions. A sp alling-off type or a deformation failure with many cracks and deformat ion bands beside the striation was found.