Study of thermal stability and mechanical properties of fcc phase Zr22W19N58 thin films deposited by reactive magnetron sputtering

Thermal stability and mechanical properties of zirconium tungsten nitride (Zr–W–N) thin films have been studied. Nano-structured Zr–W–N thin films have been deposited on Si (100) substrates by reactive magnetron sputtering at varying substrate temperatures Ts (100°–600 °C). For 100 °C ≤ Ts ≤ 600 °C, X-ray diffraction patterns of the films show a crystalline fcc phase with (111) and (200) preferred crystallographic orientations of grains. Maximum wear resistance (H/Er ~ 0.22) and maximum resistance to fatigue fracture (H3/Er2 ~ 1.0 GPa) have been obtained for the film deposited at Ts = 400 °C. Post annealing of the films deposited at 400 °C has been carried out in air from 100°–600 °C. Oxygen starts to be incorporated at 300 °C and films begin to peel off above 400 °C due to increase in oxygen incorporation. Hardness and elastic modulus of annealed films increase with increasing strain.