Effect of Zr content on structure and mechanical properties of (CrTaNbMoV)Zrx high-entropy alloy films

Highlights: • (CrTaNbMoV)Zrx films are prepared by magnetron sputtering CrTaNbMoV mosaic target and Zr target. • The structure of the films evolves from BCC to amorphous phase as Zr content increased. • The δ of amorphous phase is remarkable large that the value of BCC phase. • The (CrTaNbMoV)Zrx film with the Zr content of 30.04 at% exhibits superior wear resistance. -- Abstract: In this paper, the influence of Zr content on the phase formation, morphology, hardness and tribology behavior of (CrTaNbMoV)Zrx films are systematically investigated. The XRD results indicate that the (CrTaNbMoV)Zrx films are evolved from BCC to amorphous phase. The thermodynamic $\Delta S_{mix}$, $\Delta H_{mix}$ and VEC of amorphous are similar to BCC structure, while the atomic radius mismatch (δ) of amorphous phase is remarkable large that the values of BCC phase. FESEM shows that the top surface grain size is decreased and the cross-section becomes much denser and compacted with increasing Zr content. With an increase of the Zr content in the films, the hardness and modulus are slightly increased and reaches maximum values of 11.6 GPa and 215.6 GPa, respectively. The friction coefficient and wear rate are decreased with increasing of Zr content and the wear rate of Zr content with 30.07 at% decreases 25% that the film without Zr addition.