Structural and Mechanical Performance of Additive-Manufactured Al-Ti-Zr-Nb-V-Cr High-Entropy Alloy
摘要
High-entropy alloys (HEAs) Al-T-iZ-rNb-V-Cr are promising materials for high-temperature applications; however, precipitation of brittle phases reduces their long-term thermal stability. This material was fabricated using a direct energy deposition process (laser-engineering net shape). Evaluation of the fabricated samples was conducted via x-ray diffraction, scanning electron microscopy, and mechanical testing. Based on structural and phase investigations, chemical inhomogeneity within the HEA influences phase formation and, consequently, its properties. The electrical properties of the HEAs were assessed via the density of states and band structure. Hardness and strength were evaluated at both ambient and elevated temperatures. The results revealed microstructures with multiple phases, specifically identifying BCC solid solutions (AlNbTiV) and ordered B2 phases (AlCrNbTiV) alloys and some intermetallic compounds (B2 and Cr2Nb-C14 laves phases). Additionally, the average elastic modulus of samples A, B, and C was recorded as 110.20, 95.50, and 25.05 GPa, respectively. Therefore, these HEAs exhibit a remarkable combination of mechanical and electrical properties at both ambient and elevated temperatures, making them highly attractive for aerospace and energy storage applications.