Nanomechanical and nanotribological behaviors of hafnium boride thin films

Publication date: 30 November 2015
Source:Thin Solid Films, Volume 595, Part A
Author(s): Shahla Chowdhury, Kyriaki Polychronopoulou, Andrew Cloud, John R. Abelson, Andreas A. Polycarpou
Nanocrystalline HfB2, HfBN and multilayer HfB2/HfBN films were deposited using chemical vapor deposition. Half of the amorphous as-deposited films were subjected to annealing at 700°C to obtain their annealed equivalent samples. Nanoindentation and nanoscratch experiments were performed to measure their mechanical properties, friction and scratch/wear behavior. The annealed films showed higher hardness values compared to the as-deposited films, with the HfB2 film exhibiting the highest hardness. All three films exhibited similar shear strength around 3GPa for as-deposited and 5.5GPa for annealed films, implying reduced delamination propensity for the annealed samples. The annealed HfBN and multilayer HfB2/HfBN films exhibited lower friction and wear, compared to the rest of the films. Specifically, the annealed multilayer HfB2/HfBN films, exhibited an order of magnitude lower wear, compared to the HfB2 films, making them excellent candidates for low friction and low wear hard coating applications.