Novel Co-free high performance TRIP and TWIP medium-entropy alloys at cryogenic temperatures

摘要

Recently,high-and medium-entropy alloys(HEAs and MEAs) have been found to exhibit excellent cryogenic mechanical properties,but most of them contain high-priced Co element.Therefore,developing HEAs or MEAs with high strength and ductility and relatively low cost is urgent.In this work,novel Cofree Fex Mn(75-x) Ni(10)Cr(15)(x=50 and 55 at.%) MEAs were developed,which exhibit a good combination of low cost,high strength and ductility at cryogenic temperature.It was found that the Fe(50)Mn(25)Ni(10)Cr(15)MEA exhibits a combination of cryogenic tensile strength of^0.98 GPa and ductility of^83 %.The excellent cryogenic mechanical properties were attributed to joint of twinning-induced plasticity(TWIP) and transformation-induced plasticity(TRIP) effects.The present study sheds light on developing low cost MEAs with high perfo rmance for cryogenic-tempe rature applications.