一种超高强韧性富Fe多主元合金组织性能研究

Investigation on microstructure and properties of an ultra-strong ductile Fe-rich multi-principal component high-entropy alloy

研究了富Fe的多主元合金(高熵钢)的组织性能,发现Fe40Ni30Co10Cr8Al5Ti7合金通过冷轧及时效热处理后,在室温下可获得优异的拉伸性能,屈服强度达到1750MPa,伸长率达到11%。观察得知,冷轧及时效处理态微观组织由面心立方基体的异质结构和共格析出的L12结构有序强化相组成。通过观察分析,该合金通过细晶体强化、位错强化,以及有序相沉淀强化的综合作用,可获得优异的力学性能,而在形变过程中高密度层错产生的应变强化,使合金获得优异的塑性,凸显了L12结构有序强化相对于Fe的多主元合金(高熵钢)产生的强韧化作用。

This study has investigated the microstructure and properties of Fe-rich multi-principal-element alloys(high entropy steels).It was found that excellent tensile properties can be obtained at room temperature through cold rolling and aging heat treatment in Fe40Ni30Co10Cr8Al5Ti7,with a yield strength of 1750MPa and a uniform tensile elongation of 11%.The microstructure of the alloy after cold rolling and aging heat treatment was observed to be composed of a heterogeneous structure of a face centered cubic(FCC)matrix and a precipitated L12-structure strengthening phase.The ultrahigh yield strength is the result of the combination of refined-grain strengthening,dislocations strengthening and precipitation-hardening.The high-density stacking faults generated during deformation resulted in excellent tensile ductility of the alloy.This study shows the importance of L12-type ordered precipitates on the improvement of strength and plasticity on the Fe-rich multi-principal-element alloys(high entropy steels).