凝固速率对AlCoNiCrFe合金组织结构及性能的影响

The Effects of Solidification Rate on Microstructures and Performance of AlCoNiCrFe Alloy

采用X-Ray衍射仪、金相显微镜、室温压缩测试、显微硬度测试手段,研究了AlCoNiCrFe高熵合金在三种不同凝固速率状态下形成合金的显微组织和力学性能影响。结果表明:AlCoNiCrFe高熵合金经不同凝固速率后因高熵效应及元素扩散困难而形成简单的BCC晶体结构,合金的晶格常数随凝固速率的升高而增大。凝固速率越高合金的组织变得越细小,喷铸后合金生成梅花状树枝晶。合金的压缩强度、硬度随凝固速率升高而增大,喷铸成直径为2mm的合金其综合力学性能最好,其硬度比母合金锭提高13.6%,其塑性达到最大38.1%。

The microstructures and mechanical properties of AICoNiCrFe high-entropy alloy forming at three different solidification rates were studied by X-Ray diffraction （XRD）, optical microscopy, room temperature compression test, microhardness testing means. The results show that the formed alloy at different solidification rates have simple BCC crystal structure due to the effect of high entropy and the element diffusion difficulties, the lattice constant of the alloy increases with the solidification rate increasing. Spray casting alloy genernated plum-like dendrites, and the microstructure becomes fine, and the compression strength and hardness increases with the solidification rate increasing. The specimens of diameter of 2mm show the best mechanical properties, the hardness is increased by 13.6%, and the plasticity is up to 38.1%.