摘要
Cast Cr Co Ni Alx(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.
Cast CrCoNiAIx (x=0-1.2) medium-entropy alloys (MEAs) were produced by arc melting and flip cast to investigate the alloying effect of AI 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 AI 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 AI addition. A very interesting phenomenon of very weak ordered FCC (001) spots appearing in AI-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.
作者
Qiang Hu
Fu-chu Liu
Qian-lu Fan
Hui Du
Gang Liu
Guang-hua Wang
Zi-tian Fan
Xin-wang Liu
Qiang Hu;Fu-chu Liu;Qian-lu Fan;Hui Du;Gang Liu;Guang-hua Wang;Zi-tian Fan;and *Xin-wang Liu(State Key Laboratory of Materials Processing and Die and Mould Technology,Huazhong University of Science and Technology,Wuhan 430074,China;Department of Mechanical Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;School of Materials Science and Engineering,Xi 'an University of technology,Xi 'an 710048,China)
基金
financially supported by the National Nature Science Foundation of China(51775204 and 51604222)
the Analytical and Testing Center,HUST
China Postdoctoral Science Foundation Funded Project