Indentation Strain Rate Sensitivity of CoCrFeNiAl0.3 High‐Entropy Alloy. Issue 2 (18th October 2018)

• Record Type: Journal Article
• Authors: Qiu, Ji; Xiao, Gesheng; Jin, Tao; Su, Buyun; Shu, Xuefeng; Ma, Shengguo
• Is Part Of: Advanced engineering materials. Volume 21:Issue 2(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-10-18
• Subjects: high‐entropy alloy -- nanoindentation -- size effect -- strain rate sensitivity; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201800744
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : In this paper, the mechanical properties of CoCrFeNiAl0.3 high‐entropy alloy (HEA) under different strain rates are investigated using nanoindentation at room temperature. Experimental results show that the contact stiffness increases almost linearly with indentation depth and the elastic modulus is invariable under different indentation strain rates, while the indentation hardness under higher strain rate is relatively larger, and the hardness under large indentation depth is relatively smaller for each indentation strain rate. The indentation size effect of hardness and strain rate sensitivity exponent m under different indentation strain rates are analyzed, then the hardness and m free from the effect of indentation depth are obtained. Finally, this investigation reveals the size effects of the hardness of HEA in light of the strain rate sensitivity and activation volume of the dislocation nucleation. Abstract : The strain rate sensitivity and indentation size effect of CoCrFeNiAl0.3 are investigated. Indentation strain rate has a negligible effect on the indentation contact stiffness and elastic modulus, whereas the hardness exhibits strain rate sensitivity. The strain rate sensitivity exponent free from the effect of indentation depth is obtained.