Tribological properties of Al/AlN multilayers prepared by magnetron sputtering technique

Multilayers have been paid extensive attention to the triblogical applications due to their excellent mechanical properties and anti-wear properties. Al, AlN single layer and Al/AlN multilayers were prepared by magnetron sputtering method. The mechanical and wear properties of the multilayer were discussed. The hardness of the Al/AlN multilayer films was determined using a nano-indentation tester. The tribological properties of the films were measured by a UMT-2MT tester in reciprocating mode. The as-deposited Al/AlN multilayers show well-defined multilayer modulation structures. The mechanical properties of the Al/AlN multilayers significantly improved, which is caused by the large content of interfaces. The hardness of the Al/AlN multilayers is 8.8 GPa, which is higher than the calculated hardness (6.6 GPa) using the rule-of-mixture with the single layer. In the Al/AlN multilayers, the hard AlN layer shows superior carrying capacity, while the soft Al layer plays a lubricant role in the wear process. Therefore, the Al/AlN multilayers show lower friction coefficient (0.15) and much better wear resistance than the single layers. © 2016, Editorial Office of CHINA SURFACE ENGINEERING. All right reserved.