Theoretical and Experimental Studies of the Structural, Phase Stability and Elastic Properties of AlCrTiFeNi Multi-Principle Element Alloy

• Published in: Materials Vol. 13; no. 19; p. 4353
• Main Authors: Liu, Li, Paudel, Ramesh, Liu, Yong, Zhao, Xiao-Liang, Zhu, Jing-Chuan
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 30.09.2020; MDPI
• Subjects: AlCrTiFeNi multi-principle element alloy; Alloying elements; Alloys; Crystal structure; Deformation; Density functional theory; Ductility; Elastic properties; Enthalpy; First principles; High temperature; Intermetallic compounds; Materials science; Metallurgy; micro mechanism; Microstructure; Occupancy; Phase stability; Rare earth elements; Scanning electron microscopy; Solid solutions; Structural stability; structure; Germany
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma13194353

The fundamental challenge for creating the crystal structure model used in a multi-principle element design is the ideal combination of atom components, structural stability, and deformation behavior. However, most of the multi-principle element alloys contain expensive metallic and rare earth elements, which could limit their applicability. Here, a novel design of low-cost AlCrTiFeNi multi-principle element alloy is presented to study the relationship of structure, deformation behavior, and micro-mechanism. This structured prediction of single-phase AlCrTiFeNi by the atomic-size difference, mixing enthalpy ΔHmix and valence electron concentration (VEC), indicate that we can choose the bcc-structured solid solution to design the AlCrTiFeNi multi-principle element alloy. Structural stability prediction by density functional theory calculations (DFT) of single phases has verified that the most advantageous atom occupancy position is (FeCrNi)(AlFeTi). The experimental results showed that the structure of AlCrTiFeNi multi-principle element alloy is bcc1 + bcc2 + L12 phases, which we propose as the fundamental reason for the high strength. Our findings provide a new route by which to design and obtain multi-principle element alloys with targeted properties based on the theoretical predictions, first-principles calculations, and experimental verification.