Microst met lire and tribological properties of CrTiAIN composite coatings with high Cr content on 65Mn steels deposited by multi arc ion plating technology

摘要

The CrTiAIN composite coatings with different chemical composition are deposited on the surface of 65Mn steels by multi-ion plating technology in a gas mixture of Ar+N_2. The Metallic ratio of Cr, Ti, and Al was varied by adjusting the currents of different TiAl target. The coatings were characterized by means of energy dispersive X-ray(EDX) analysis, X-ray diffractmetry(XRD), scanning electronic microscopy(SEM), microhardness tester, and ball-on-disc tribometer , respectively. The experimental results show that the surface morphology of CrAlTiN films are compact and dense. And the cross-section morphology appears as fibrous columnar crystals structure. Compared with CrN coatings, the preferential growth orientation of CrAlTiN films was changed from CrN (111) to CrN (200) after the addition of Ti, Al element. When the TiAl target arc current was 50A, the hardness reach the maximum value, 35GPa. The CrAlTiN composite films performs better than binary CrN as well as the Cr plating in teams of hardness and wear resistance at high temperature. Then the tribological mechanisms at high temperature for the above three kinds of coatings was discussed.