Enhancing Mechanical Properties of a Lightweight TiAlCrNbVZr Medium-Entropy Alloy: Fine-Tuning Alloy Composition and Thermomechanical Treatment

2024-03-04T09:39:55+00:00

Abstract: The quest to reduce fuel consumption and environmental pollution in the transportation sector has heightened the demand for developing lightweight alloys with enhanced mechanical properties. Accordingly, this study focused on optimizing the mechanical properties of a lightweight Ti₆₅(AlCrNbV)₂₈Zr₇ medium entropy alloy (MEA) by strategically adjusting its Al, Cr, Nb, and V elemental contents. Hardness testing indicated a strengthening ability hierarchy of Cr > Al > V > Nb. Furthermore, tensile tests revealed that although a high Cr content significantly enhances strength, it also reduces the ductility of an MEA. Drawing on mechanical insights gained from a previously studied Ti₆₀Al₁₀Cr₁₀Nb₁₀V₁₀ MEA and the present findings, a novel Ti₆₀Al₁₀Cr₄Nb₁₀V₉Zr₇ (Ti60Zr7) MEA was developed. This new alloy retains a single body-centered cubic structure and demonstrated exceptional mechanical performance in tensile testing, with a yield strength of 1066 MPa and 22% ductility. The Ti60Zr7 MEA underwent a series of thermomechanical treatments, including 50% hot rolling, 80% cold rolling, and rapid annealing up to 800 °C at a rate of 25 °C/s. After thermal processing, the Ti60Zr7 MEA not only preserved its single body-centered cubic structure but also achieved a remarkable combination of yield strength (>1200 MPa) and ductility (measured as >15% elongation). These advancements underscore the alloy’s considerable potential for application in sports equipment and transportation vehicles.

Journal of Material Science and Technology Research

Enhancing Mechanical Properties of a Lightweight TiAlCrNbVZr Medium-Entropy Alloy: Fine-Tuning Alloy Composition and Thermomechanical Treatment