l(0.2)CoCrFeNiSc(x) (x=0, 0.1, 0.2 and 0.3, molar fraction) alloys were prepared by arc melting. The effects of Sc addition on the microstructure, phase evolution and mechanical properties of Al0.2CoCrFeNiScx alloys were investigated. The results showed that Sc could refine grain size, change phase type and improve mechanical properties. The grain size of Al0.2CoCrFeNiSc0.3 alloy (8.5 mu m) was reduced by approximately 50.6% compared to that of Al0.2CoCrFeNiSc0.1 alloy (17.2 mu m). The crystal structure evolved from a single FCC phase to a mixed phase including two types of FCC phases and one type of BCC phase. The FCC phase mainly appeared in the regions of (Co, Cr, Fe)- rich dendrites and (Ni, Sc)-rich interdendrites; while the BCC phase was mainly located in the region of (Al, Ni)-rich interdendrites. The yield strength increased from 167 to 717 MPa as the x value in Al0.2CoCrFeNiScx alloy increased from 0 to 0.3, improved by 329.3%, which could be attributed to grain size strengthening, solid solution strengthening and phase evolution.

采用电弧熔炼法制备Al_(0.2)CoCrFeNiSc_x (x=0, 0.1, 0.2, 0.3,摩尔分数)合金，研究Sc添加对合金显微组织、相演变和力学性能的影响。结果表明，Sc能细化晶粒、改变相类型以及提高合金的力学性能。相较于Al_(0.2)CoCrFeNiSc_(0.1)合金的晶粒尺寸(17.2μm),Al_(0.2)CoCrFeNiSc_(0.3)合金的晶粒尺寸仅为8.5μm，减小了约50.6%。合金的晶体结构由FCC相演变为包括两种FCC相和一种BCC相的混合相。FCC相主要出现在富Co、Cr和Fe枝晶区域和富Ni和Sc枝晶间区域，而BCC相主要出现在富Al和Ni枝晶间区域。当Al_(0.2)CoCrFeNiSc_x合金中x值由0增加到0.3时，合金的屈服强度由167 MPa增加至717 MPa，提高了329.3%，这主要归因于晶粒强化、固溶强化和相演变。