Structure evolution and mechanical properties of Ta–Nb–Ti–W–N multielement films

Abstract

In this study, the multielement films (Ta_50·5Nb_16·7Ti_8·8W_24·0)N, (Ta_25·4Nb_13·4Ti_20·9W_40·3)N and (Ta_9·3Nb_4·7Ti_22·6W_63·4)N are prepared by combining magnetron sputtering deposition and nitrogen plasma based ion implantation (N-PBII). The composition, structure and mechanical properties of the films are investigated. X-ray diffraction patterns show that the alloy films Ta_50·5Nb_16·7Ti_8·8W_24·0, Ta_25·4Nb_13·4Ti_20·9W_40·3 and Ta_9·3Nb_4·7Ti_22·6W_63·4 are composed of hcp+bcc, two types of bcc and a single bcc solid solution respectively, whereas all the Ta–Nb–Ti–W films are composed of bcc and fcc structures after N-PBII treatment. The lattice constant increases for both the bcc and fcc phases, while it decreases for the Ta and Nb concentrations in the films. The hardness and modulus of the Ta–Nb–Ti–W–N films are improved with increasing nitrogen implantation dose. The wear rate of the Ta_25·4Nb_13·4Ti_20·9W_40·3 with nitrogen implantation for 1 h is decreased two times than the Ta_25·4Nb_13·4Ti_20·9W_40·3 alloy films.

Keywords:

• Multielement films
• Structure
• Hardness
• Wear