淬火温度对Al_(0.5)CoCrFeNiSi_(0.2)高熵合金组织结构的影响  

Effect of Quenching Temperature on the Microstructure of High-entropy Al_(0.5)CoCrFeNiSi_(0.2) Alloy

作　　者：吴桂芬[1] 唐群华[1] 柯跃前[2] 戴品强[1,3] 吴波[1] 

机构地区：[1]福州大学材料科学与工程学院,福建福州350108 [2]泉州师范学院物理与信息工程学院,福建泉州362000 [3]福建工程学院材料科学与工程系,福建福州350108

出　　处：《材料科学与工程学报》2012年第3期422-427,共6页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(50971043;51171046)

摘　　要：采用真空电弧熔炼的方法制备了高熵合金Al0.5CoCrFeNiSi0.2。对其进行600℃到1100℃保温10h后淬水的淬火处理。通过金相显微镜、扫描电镜及附带的能谱仪、X射线衍射仪和透射电镜观察分析合金的组织结构。用显微硬度计测定合金的显微硬度。结果表明:铸态和淬火态的合金组织均呈典型的枝晶形貌,枝晶含有非晶相和纳米级颗粒。在淬火加热温度低于800℃时,随着淬火温度升高,晶粒细化、fcc相含量减少,硬度随淬火温度的升高而提高;当温度升高至900℃后,枝晶相长大,fcc相含量增加,大块枝晶中析出一种富含Al、Ni的θ相,硬度下降。High-entropy Al0.5CoCrFeNiSi0.2 alloy was prepared by the arc melting and casting method.As-cast alloy was heated at 600℃-1 100℃ for 10h and subsequently quenched into water.Microstructure of the alloy was characterized by optical microscopy（OM）,scanning electron microscopy（SEM）,X-ray energy-dispersive spectrometry（EDS）,X-ray diffractometry（XRD） and transmission electron microscopy（TEM）.Hardness of the alloy was measured by a Vickers hardness tester.The results showed that the microstructures of as-cast and as-quenched alloy exhibited typical dendrite and inter-dendrite structures.Dendrites contained an amorphous phase and nano-scale precipitates.When the quenching temperature is lower than 800℃,the hardness of the as-quenched alloy increased with increasing quenching temperature,this can be attributed to dendrite refinement,inter-dendrite phase increase and decrease of the fcc phase.When the quenching temperature is higher than 900℃,the dendrite phase grew up,the fcc phase increased and a Ni-Al rich phase precipitated in the dendrites,which resulted in the hardness of alloy to decrease.

关 键 词：高熵合金 淬火温度 微观组织 

分 类 号：TG115.2[金属学及工艺—物理冶金]