Abstract
In this study, a new design of refractory high-entropy alloy, MV series, for nuclear structure materials is developed. The melting point is around 2000 ˚C. The density is around 7 g/cm3. Macro neutron absorption cross section is around 0.17 cm-1, which is less than SS304 by 30%. Simple BCC structure is observed in the as-cast state of this alloy. The formation of simple solid solution phase mainly results from the high entropy effect and low bonding energies among constituent elements. After 1200 ˚C/12 h heat treatment, MV075 and MV100 will form Laves phase precipitation, but MV030 and MV050 won’t. These alloys have Vickers hardness around 350 to 450 Hv and compression yield strength around 1000 to 1400 MPa. Impressively, MV030-C and MV050-C possess the compression ductility more than 50%. By the high temperature compression test, MV050-C shows good thermal-softening resistance until 800 ˚C, retaining 850 MPa. Comparing to HfNbTaTiZr alloy, MV050-C and HfNbTaTiZr both possess the compression ductility more than 50%, but MV050-C have better compression yield strength until 800 ˚C and better specific yield strength.