The hardness and wear properties of Ti-Mo-C-N films were investigated by nanoindentation and ball-on-disc measurements, respectively. Ti-Mo-C-N films were deposited onto a stainless steel substrate by a reactive RF magnetron sputtering in the mixture of argon (7.5 ccm) and nitrogen (0-6.0 ccm) gases using Ti25Mo25C50 target. Ti-Mo-C film deposited without nitrogen gas flow showed a hardness of 34.8 GPa. The hardness drastically decreased with increasing nitrogen gas flow rate (/n2) and reached to a minimum hardness of 16.4 GPa at fN2=2.0 ccm. Contrarily, at overf N2=3;0 ccm, the hardness drastically increased with increasingf N2 and reached a maximal value of 32 GPa, and then slightly decreased again with further increase of fn2. It was found by TEM observation that the drastic decrease in hardness is caused by the formation of nanocrystalline microstructure, while the increase in hardness is due to the microstructural change from nanocrystalline to columner structure. The friction coefficient decreased with increasing fn2 and the film deposited at fN2=5.0 ccm showed a minimum value of 0.27. The simple oxidation test in air indicated that lubricious M0O3 is easy to be formed in the film deposited at a high/N2, which should cause the reduction of friction coefficient.
|Number of pages||7|
|Journal||Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals|
|Publication status||Published - 2015 Apr 1|
- Friction coefficient
- Wear resistance