Abstract
Ti/Mo and Cr/Mo metallic multilayer films with different periodicities were synthesised on a Ti–6Al–4V alloy surface by ion beam enhanced magnetron sputtering deposition process. The structure, bonding strength, microhardness and ductility of the multilayer films were measured. The effects of Ti/Mo and Cr/Mo metallic multilayer films on wear and fretting fatigue (FF) resistance of Ti–6Al–4V were studied. The results show that the wear resistance of Ti–6Al–4V alloy is improved by the Ti/Mo and Cr/Mo multilayer films which exhibit high density, fine grain, high bonding strength and obvious superhardness phenomenon. Ti/Mo multilayer films with a 200 nm periodicity exhibit strong adhesion, high hardness, good toughness and excellent fatigue resistance, which bring a 30% increase in FF life of Ti–6Al–4V alloy. However, Cr/Mo multilayer films have only a minor effect on the FF resistance of the Ti–6Al–4V alloy due to their high hardness and low ductility.
This research work was supported by National High Technical Research and Development Programme of China (grant no. 2007AA03Z521) and National Natural Science Foundation of China (grant no. 50771070 and no. 50671085).