Study of the texture and residual stresses in multilayer Nb/Mo coatings obtained by inverted magnetrons

Abstract

This work is devoted to the study of the formation of the structure, crystallographic texture and residual stresses in multilayer Nb/Mo coatings deposited by inverted magnetrons on a tubular substrate made of a chromium-nickel alloy. Microprobe analysis of the obtained samples did not show the presence of Nb–Mo solid solutions resulting from mutual diffusion, which is most likely caused by low heating of the coating material during deposition. The results of the studies show that in the outer layers of the multilayer coating, residual stresses are characterized by relatively low values. It is likely that the alternation of layers of refractory metals that differ in thermal linear expansion coefficient values leads to mutual compensation of thermal stresses. Thus, the value of the residual stresses of a multilayer coating of any thickness is comparable to a two-layer coating. The texture effect in a multilayer coating is insignificant compared to the effect of solid solution formation, so high-temperature annealing will help to equalize the elastic characteristics and, accordingly, the stress state in the coating.