Nanoindentation Creep Behavior of an Al0.3CoCrFeNi High-Entropy Alloy

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Physical metallurgy and materials science, 2016-12, Vol.47 (12), p.5871-5875
• Main Authors: Zhang, Lijun, Yu, Pengfei, Cheng, Hu, Zhang, Huan, Diao, Haoyan, Shi, Yunzhu, Chen, Bilin, Chen, Peiyong, Feng, Rui, Bai, Jie, Jing, Qin, Ma, Mingzhen, Liaw, P. K., Li, Gong, Liu, Riping
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Materials Science; Metallic Materials; Nanotechnology; Structural Materials; Surfaces and Interfaces; Symposium: Micromechanics of Advanced Materials III in Honor of J.C.M. Li; Thin Films
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-016-3469-8

Nanoindentation creep behavior was studied on a coarse-grained Al 0.3 CoCrFeNi high-entropy alloy with a single face-centered cubic structure. The effects of the indentation size and loading rate on creep behavior were investigated. The experimental results show that the hardness, creep depth, creep strain rate, and stress exponent are all dependent on the holding load and loading rate. The creep behavior shows a remarkable indentation size effect at different maximum indentation loads. The dominant creep mechanism is dislocation creep at high indentation loads and self-diffusion at low indentation loads. An obvious loading rate sensitivity of creep behavior is found under different loading rates for the alloy. A high loading rate can lead to a high strain gradient, and numerous dislocations emerge and entangle together. Then during the holding time, a large creep deformation characteristic with a high stress exponent will happen.