(1. 桂林电子科技大学 广西信息材料重点实验室,桂林 541004;
2. 哈尔滨工业大学 材料科学与工程学院,哈尔滨 150001)
摘 要: 利用非自耗真空电弧熔炼技术,研究等摩尔Mn、V、Mo、Ti、Zr元素对AlFeCrCoCu多组元高熵合金的组织结构、硬度及抗高温氧化性能的影响。结果表明:6组合金都是典型的树枝晶结构,合金组织成分偏析严重,Cu元素大量聚集在晶间,其中,Ti和Zr元素对合金的组织影响最大,两组合金都伴随富Cr组织析出。合金具有较强的硬度,其硬度均与添加元素原子半径成正比。热重分析实验表明:合金具有较强的抗高温氧化能力,在加热到700 ℃以前,质量几乎保持不变,AlFeCrCoCu合金的抗高温氧化性能最好,而第6元素的添加对合金的抗高温氧化能力不利。其中,V和Mo元素的加入导致其产生的对应氧化物具有易挥发特性而严重地恶化合金的抗高温氧化性能。
关键字: 高熵合金;显微组织;硬度;热分析;高温氧化
(1. Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, China;
2. School of Materials Science and Engineering, Harbin Industrial University, Harbin 150001, China)
Abstract:A series of AlFeCrCoCu-X high-entropy alloys that X represents the Mn, V, Mo, Ti, Zr elements fabricated by an arc remelter were investigated by XRD, SEM, EDS, DSC and TG . The results show that 6 kinds of alloys exhibit dendritic structure, Cu preferentially segregates to the interdendritic regions, and the Cr-rich phase precipitates with adding Ti or Zr. The alloys have high hardness value, and their hardness increases with increasing the doped element radius. The alloys have strong ability to resist high temperature oxidation, their quality almost remain the same before heating to 700 ℃. The high temperature oxidation resistance of AlFeCrCoCu alloy is the best, and doping elements can reduce the high temperature oxidation resistance, Mo-oxides and V-oxides are volatiles that disrupt the formation of a protection scale and deteriorate the high temperature oxidation resistance of alloys.
Key words: high-entropy alloy; microstructure; hardness; thermoanalysis; high temperature oxidation