Integration of hardness and toughness in (CuNiTiNbCr)Nx high entropy films through nitrogen-induced nanocomposite structure

The high-entropy alloy films show excellent comprehensive properties and have great application prospects in space, polar, deep-sea exploration. Compared with traditional ceramic films, the application of high-entropy alloy films is limited by the relative low hardness. In this paper, based on the nanocomposite structure formation principle in thermodynamics, we design the nanocomposite (CuNiTiNbCr)Nx films (HEFs). The introduced N atoms react with Ti, Nb, Cr to form (TiNbCr)N phase (accompanied by Cu and Ni segregation), and the structure of the HEFs changes from amorphous to a nanocomposite structure of CuNi-rich amorphous matrix-(TiNbCr)N nanocrystalline phase. The nanocomposite HEFs exhibit high hardness, high toughness, and excellent wear performance. These results indicate that nanocomposite HEFs have potential applications in the field of extreme environmental wear protection.