AlCoCrFeNi高熵合金中Al原子的扩散行为  

Diffusion Behavior of Al Atoms in AlCoCrFeNi High-entropy Alloy

作　　者：李根 施健东 田春茂 庄艳歆[2] LI Gen;SHI Jiandong;TIAN Chunmao;ZHUANG Yanxin(School of Materials Science and Engineering,Northeastern University,Shenyang 110004,China;EPM Key Laboratory of Ministry of Education,Northeastern University,Shenyang 110004,China)

机构地区：[1]东北大学材料科学与工程学院,辽宁沈阳110004 [2]东北大学材料电磁过程研究教育部重点实验室,辽宁沈阳110004

出　　处：《热加工工艺》2021年第18期37-41,共5页Hot Working Technology

基　　金：中央高校基本科研业务专项资金项目(N182410001);国家级大学生创新创业训练计划资助项目(201910145255)。

摘　　要：高熵合金是近几年发展起来的新型金属材料,高熵合金的扩散迟滞效应使其具有较好的热稳定性及高温抗氧化性,对其扩散行为的研究对理解高熵合金的相形成、组织和性能演化有重要意义。以AlCoCrFeNi系高熵合金为研究对象,将纯Al和Al_(6.97)Co_(23.26)Cr_(23.26)Fe_(23.26)Ni_(23.26)高熵合金制成扩散偶,研究不同温度下Al在AlCoCrFeNi高熵合金中的扩散行为。利用电子探针检测扩散层的形貌和成分分布,计算了扩散系数和扩散激活能。结果表明:当温度低于723K时,Al与Al_(6.97)Co_(23.26)Cr_(23.26)Fe_(23.26)Ni_(23.26)高熵合金间的元素扩散速率非常慢,在扩散偶的界面处未发现新相的形成;当温度在773~873 K时,在Al与高熵合金的界面处形成明显的扩散反应层,扩散反应层内有新相形成;Al在Al_(6.97)Co_(23.26)Cr_(23.26)Fe_(23.26)Ni_(23.26)高熵合金的扩散激活能为(50.9±6.8)kJ/mol;扩散距离随温度的升高而增大。High entropy alloy is a new type of metal material developed in recent years.The diffusion hysteresis effect of high entropy alloy makes it have better thermal stability and high temperature oxidation resistance.The study of its diffusion behavior is of great significance to understand the phase formation,microstructure and property evolution of high entropy alloy.AlCoCrFeNi system high entropy alloy is taken as the research object.Pure Al and Al_(6.97)Co_(23.26)Cr_(23.26)Fe_(23.26)Ni_(23.26)high entropy alloy are made into diffusion couple.The diffusion behavior of Al in AlCoCrFeNi high entropy alloy at different temperatures was studied.The morphology and composition distribution of the diffusion layer were measured by EPMA,and the diffusion coefficient and diffusion activation energy were calculated.The results show that the diffusion rate of elements between Al and Al_(6.97)Co_(23.26)Cr_(23.26)Fe_(23.26)Ni_(23.26)high entropy alloy is very slow when the temperature is lower than 723 K,and no new phase is found at the interface of diffusion couple;when the temperature is between 773-873 K,an obvious diffusion reaction layer is formed at the interface of Al and high entropy alloy,and new phase is formed in the diffusion reaction layer.The diffusion activation energy of Al_(6.97)Co_(23.26)Cr_(23.26)Fe_(23.26)Ni_(23.26)high entropy alloy is(50.9±6.8)kJ/mol,and the diffusion distance increases with the increase of temperature.

关 键 词：高熵合金 扩散 扩散反应层 界面 扩散激活能 

分 类 号：TG132[一般工业技术—材料科学与工程] TG111.6[金属学及工艺—合金]