Mechanical and tribological characterization of nanostructured HfB_2 films deposited from compound target

摘要

Fabrication and development of HfB_2-based nanostructured coatings was investigated. All films were deposited onstainless-steel substrates by RF magnetron sputtering from stochiometric HfB_2target in argon atmosphere. The aim ofthis work is to evaluate the effects of the bias potential on the microstructure, mechanical and tribological properties.These parameters strongly depend on the experimental conditions. X-ray diffraction analysis indicated the difference inmicrostructure: from dense hexagonal structure with (0001) preferred orientation of nanocrystallites to quasi-amorphouswith blurred HfB_2phase peaks. All coatings were measured using nanoindentation (using Berkovich tip), tribology (ballon-disk) and nano-scratch (friction). Coatings with a thickness of 1–2 μm had a significant dependence of properties onthe microstructure: hardness drastically increased from 8 to 45 GPa, H/E ratio and elastic recovery changed respectively:0.04–0.15 and 0.26–0.72.