Effect of Zr addition on microstructure and mechanical properties of CoCrFeNiZrx high-entropy alloy thin films

• Published in: Applied nanoscience Vol. 11; no. 3; pp. 771 - 776
• Main Authors: Feng, Xiaobin, Fan, Sufeng, Meng, Fanling, Surjadi, James Utama, Cao, Ke, Liao, Weibing, Lu, Yang
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 2021; Springer Nature B.V
• Subjects: Alloying effects; Alloys; Amorphous alloys; Amorphous structure; Chemistry and Materials Science; Crystal structure; Direct current; Hardness; High entropy alloys; Lattices; Magnetron sputtering; Materials Science; Mechanical properties; Membrane Biology; Metallic glasses; Microstructure; Nanochemistry; Nanotechnology; Nanotechnology and Microengineering; Original Article; Phase transitions; Solid phases; Thin films; Thin films; High-entropy alloys; Microstructure; Hardness; Sputtering; Deformation mechanism
• ISSN: 2190-5509; 2190-5517
• DOI: 10.1007/s13204-019-01057-7

As the technology of microscale devices evolves to smaller dimensions, the newly surged high-entropy alloys (HEAs), in particular high entropy alloy thin films (HEAFs), manifest excellent properties for practical applications. However, limited studies to date focused on microstructures and their impact on mechanical properties of HEAFs. In this work, we systematically investigated the relationship between microstructure and mechanical properties of CoCrFeNiZr x ( x  = 0, 0.3, 0.5, 1) high-entropy alloy thin films. A transition from single-phase crystal to amorphous structure was observed with increasing Zr concentration from 0 to 20.7 at.%. In the intermediate Zr concentration ranging from 7.0 to 12.9 at.%, Zr addition renders a crystal–amorphous dual-phase structure with Zr element segregation and a peak hardness of 6.7 GPa. These findings not only provide deep insight into understanding alloying effects on microstructure evolution and mechanical properties of HEAFs, but also present valuable information for designing ultrastrong high-entropy alloys for practical applications, such as microelectronic devices, lightweight lattices and advanced coating industry. Highlights The CoCrFeNiZr x high-entropy alloy thin films were synthesized by the direct current magnetron co-sputtering. A transition from single-phase nanocrystalline to amorphous structure was observed with increasing Zr concentration. Zr segregation occurs in amorphous region of crystal–amorphous dual-phase thin films. Compared with crystalline and amorphous thin films, the crystal–amorphous dual-phase high-entropy alloy thin film exhibits nearly double hardness/strength.