非等原子(FeCoNiCr)_(100−x)Mn_(x)高熵合金的微观组织和力学性能

Microstructure and mechanical properties of(FeCoNiCr)_(100−x)Mn_(x) non-equiatomic high-entropy alloys

设计开发了一种非等原子(FeCoNiCr)_(100−x)Mnx(x=0,12,20)高熵合金的制备工艺。结果表明:采用真空热压烧结技术制备的含Mn型(FeCoNiCr)_(100−x)Mnx合金由面心立方(FCC)和体心立方(BCC)相组成,其中有大量的纳米级金属间化合物析出。经650℃退火1h后,(FeCoNiCr)_(88)Mn_(12)合金的综合力学性能最佳,压缩屈服强度为873.65 MPa,极限抗压强度为1813.98 MPa,断裂应变为41.03%,弯曲强度为1573.69 MPa,断裂韧性为49.45 MPa·m^(1/2)。优异的力学性能归因于BCC相的强化作用以及低堆垛层错能区域所形成的大量退火孪晶。孪晶诱导塑性(TWIP)辅助的非等原子双相高熵合金设计理念,为高熵合金成分设计提供了一种新的思路。

The Non-equiatomic(FeCoNiCr)_(100−x)Mn_(x)(x=0,12,20)high-entropy alloys were studied.The results indicate that(FeCoNiCr)_(100−x)Mn_(x) alloys containing Mn prepared by vacuum hot pressing sintering present dual phase microstructure compose of the face centered cubic(FCC)/body centered cubic(BCC)phases,in which a lot of nanometer intermetallic compounds precipitate.The(FeCoNiCr)_(88)Mn_(12) alloy after annealed at 650℃for 1 h has the best comprehensive mechanical properties,with compressive yield strength of 873.65 MPa,ultimate compressive strength of 1813.98 MPa,fracture strain of 41.03%,flexural strength of 1573.69 MPa and fracture toughness of 49.45 MPa·m^(1/2).The excellent comprehensive mechanical properties are attributed to the second phase strengthening effect of BCC phases and a large number of annealing twins form in the low stacking fault energy region.The design concept of TWIP-assisted non-equiatomic dual-phase high-entropy alloys can provide a new idea for the composition design of high-entropy alloys.