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Effect of Al on microstructure and mechanical properties of cast CrCoNi medium-entropy alloy.

Authors :
Qiang Hu
Fu-chu Liu
Qian-lu Fan
Hui Du
Gang Liu
Guang-hua Wang
Zi-tian Fan
Xin-wang Liu
Source :
China Foundry; Jul2018, Vol. 15 Issue 4, p253-261, 10p
Publication Year :
2018

Abstract

Cast CrCoNiAlx (x=0-1.2) medium-entropy alloys (MEAs) were produced by arc melting and flip cast to investigate the alloying effect of Al addition on the microstructure, phase constituent and mechanical properties. The crystal structure changes from an initial face-centered cubic (FCC) to duplex FCC and body-centered cubic (BCC) and finally a single BCC with increasing Al content. In the duplex region, FCC and BCC phases form under a eutectic reaction in the interdendrite region. In the single BCC region, the dendrites transform to ordered B2 and disordered A2 BCC phases resulting from spinodal decomposition. Corresponding to their phase constituents, yield strength increases accompanied with an elongation reduction with increasing Al addition. A very interesting phenomenon of very weak ordered FCC (001) spots appearing in Al-0.4 alloy was observed, indicating a local ordering of FCC phase. The changes of fracture surfaces after the tensile deformation are also corresponding to the variations in mechanical properties. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
16726421
Volume :
15
Issue :
4
Database :
Complementary Index
Journal :
China Foundry
Publication Type :
Academic Journal
Accession number :
131215333
Full Text :
https://doi.org/10.1007/s41230-018-8031-4