The Effects of Working Pressure and Substrate Bias on the Structures and Mechanical Properties of ZrB2/AlN Multilayers

摘要

ZrB2/AlN multilayers were synthesized by radio frequency magnetron sputtering under different working pressure and substrate bias. The effects of working pressure and substrate bias on the microstructures and mechanical properties of the multilayers were characterized with XRD, SEM, Nano Indenter and profiler. The results showed that most of ZrB2/AlN multilayers displayed higher hardness and elastic modulus than the rule-of-mixture of monolithic ZrB2 and AlN coatings. When the working pressure was 0.4 Pa and substrate bias was -60 V, the multilayer possessed the highest hardness (36.8 GPa), modulus (488.7 GPa), and critical fracture load (43.6 mN). The increase of the substrate bias and decrease of the working pressure can result in an increase in energy for deposition particles, enhancing mobility of surface species, which induced an increase in areal atomic density and dislocation pinning. These changes of structure combined with small nanoscale grain sizes should be related to hardness and fracture resistance increasing.