Deposition and characterization of fine-grained W–Ni–C/N ternary films

Abstract

W–Ni–C/N ternary films with 3<at.% Ni<14 and 0<at.% C, N<30 were synthesized by reactive sputtering from a W–10 wt.% Ni target with increasing partial pressures of methane or nitrogen and substrate bias. The films have been characterized by electron probe microanalysis, X-ray diffraction, ultramicrohardness and scratch testing. The results show that the degree of structural order of the films decreases with increasing nickel and metalloid element contents. The hardness values obtained vary between 25 and 55 GPa, with a maximum for films with low nitrogen and carbon contents (6–8 at.%), deposited with a substrate bias of −70 V. The Young modulus follows the same trend as hardness, with a maximum modulus value of 550 GPa. The crystalline coatings present higher critical loads than the amorphous coatings. The more adherent coatings have critical loads higher than 70 N.