粉末冶金制备Fe28Ni28Mn28Cr8Cu8与Fe28Ni28Mn28Cr8Al8高熵合金的微观组织与力学性能

Microstructure and mechanical properties of Fe28Ni28Mn28Cr8Cu8 and Fe28Ni28Mn28Cr8Al8 high entropy alloys prepared by powder metallurgy

采用“机械合金化(MA)+放电等离子烧结(SPS)”的方法制备出Fe28Ni28Mn28Cr8Cu8和Fe28Ni28Mn28Cr8Al8两种高熵合金块体,并研究其微观组织和力学性能。结果表明:两种高熵合金均在机械合金化后形成了FCC+BCC相的合金粉末。与Fe28Ni28Mn28Cr8Cu8合金相比较,当Cu元素被Al元素取代之后,Fe28Ni28Mn28Cr8Al8高熵合金粉末中BCC结构的固溶体相含量明显增加。经SPS烧结后,Fe28Ni28Mn28Cr8Cu8由单相FCC和少量富Cr相组成;Fe28Ni28Mn28Cr8Al8则形成双相FCC结构。同时,两种高熵合金在室温下均表现出良好的压缩性能;相较于Fe28Ni28Mn28Cr8Cu8,Fe28Ni28Mn28Cr8Al8的屈服强度由716 MPa提高到1181 MPa,抗压强度由1908 MPa提高为2111 MPa,硬度也由267 HV上升到482 HV,但塑性却由38.6%降至26.1%。

Fe28Ni28Mn28Cr8Cu8 and Fe28Ni28Mn28Cr8Al8 high-entropy alloys(HEAs)were prepared by mechanical alloying(MA)and spark plasma sintering(SPS),and their microstructure and mechanical properties were studied in detail.The results show that a combination of FCC+BCC structure phases forms after MA in both HEAs.Compared with Fe28Ni28Mn28Cr8Cu8,the content of BCC-structured solid solution phase increases evidently in Al-containing Fe28Ni28Mn28Cr8Al8.After SPS sintering,one FCC and a small amount of Cr-rich phase can be observed in the bulk Fe28Ni28Mn28Cr8Cu8 HEA,while Fe28Ni28Mn28Cr8Al8 has two FCC phases.Additionally,both HEAs exhibit good compressive properties at room temperature.However,compared with Fe28Ni28Mn28Cr8Cu8,the Al-containing Fe28Ni28Mn28Cr8Al8 shows a higher strength with a lower plasticity.Compared with Fe28Ni28Mn28Cr8Cu8,the yield strength of Fe28Ni28Mn28Cr8Al8 increases from 716 MPa to 1181 MPa,the compressive strength increases from 1908 MPa to 2111 MPa,and the hardness increases from 267 HV to 482 HV,respectively,but the plasticity decreases from 38.6% to 26.1%.