选区激光熔化AlCoCrCuFeNi高熵合金的高温氧化行为研究  

High-Temperature Oxidation Behavior of AlCoCrCuFeNi High-Entropy Alloys Prepared by Selective Laser Melting

作　　者：王勇刚[1] 刘和剑[1] 董逸君 周松 王磊 职山杰[1] 李东亚[1] 王爽 Wang Yonggang;Liu Hejian;Dong Yijun;Zhou Song;Wang Lei;Zhi Shanjie;Li Dongya;Wang Shuang(Applied Technology College of Soochow University,Suzhou 215325,China;School of Mechanical and Electrical Engineering,Shenyang Aerospace University,Shenyang 110136,China;Key Laboratory of Fundamental Science for National Defense of Aeronautical Digital Manufacturing Process,Shenyang Aerospace University,Shenyang 110136,China)

机构地区：[1]苏州大学应用技术学院,江苏苏州215325 [2]沈阳航空航天大学机电工程学院,辽宁沈阳110136 [3]沈阳航空航天大学航空制造工艺数字化国防重点学科实验室,辽宁沈阳110136

出　　处：《稀有金属材料与工程》2023年第6期2154-2160,共7页Rare Metal Materials and Engineering

基　　金：江苏省高等学校自然科学研究面上项目(21KJB460020);国家自然科学基金青年基金(52105157);江苏高校“青蓝工程”优秀青年骨干教师资助项目(苏教师函[2021]11号)。

摘　　要：基于选区激光熔化技术制备了AlCoCrCuFeNi高熵合金,研究其显微组织及800、1000和1200℃下的高温氧化行为,采用X射线衍射仪和扫描电镜等方法表征分析了氧化膜的物相组成和形貌特征。结果表明:所制备的AlCoCrCuFeNi高熵合金主要包含bcc相、bcc/B2相和少量的fcc相,显微组织为长直柱状枝晶和等轴胞晶结构组成的非平衡异质结构。AlCoCrCuFeNi高熵合金在3种不同温度下的高温氧化性能优异,氧化动力学曲线基本符合抛物线定律,氧化速率对温度有明显的依赖性,其随着温度的提高而增加,并且氧化反应导致氧化膜中产生了明显的空洞和裂纹,为金属元素的持续扩散提供了通道,加剧了氧化反应,所引起的剥落现象愈加严重,氧化膜主要成分为Cr_(2)O_(3)、Al_(2)O_(3)和MCr_(2)O_(4)尖晶石混合氧化物,较为致密的氧化膜可以有效地抑制基体受到进一步氧化,提高抗氧化性能。AlCoCrCuFeNi high-entropy alloys(HEAs)were prepared by selective laser melting(SLM).The microstructure and high-temperature oxidation behavior at 800,1000 and 1200℃were studied.The phase composition and morphological characteristics of the oxide film were analyzed by XRD and SEM.The results indicate that the prepared AlCoCrCuFeNi HEAs mainly contain bcc phase,bcc/B2 phase and a small amount of fcc phase,and the microstructure is a non-equilibrium heterostructure composed of long straight columnar dendrite and equiaxed cell structures.The HEAs have good oxidation resistance at different temperatures.The oxidation kinetics curves basically follow the parabolic law.The oxidation rate exhibits a clear dependence on temperature,which increases with the increase in temperature,and obvious voids and cracks appear in the oxide films,which provide channels for diffusion of elements to aggravate the oxidation reaction;as a result,the oxide film peeling becomes more and more serious.The main components of the oxide films are Cr_(2)O_(3),Al_(2)O_(3) and spinel MCr_(2)O_(4) mixed oxides.The denser oxide film can effectively inhibit the matrix from being further oxidized and improve the anti-oxidation properties of SLMed HEAs.

关 键 词：高熵合金 选区激光熔化 高温氧化 氧化动力学 氧化膜 

分 类 号：TG139[一般工业技术—材料科学与工程]