Development of a Low-Density and High-Strength Titanium Alloy

Abstract

Weight reduction is often considered the primary goal in the development of structure materials. A new Ti-8Al-1Cr-1V-0.5Fe-0.1Si (wt.%) alloy with a low-density and a high-strength was developed in this work. The microstructures and mechanical properties of the alloy were investigated in hot-rolled and solution-aging (STA) treatment conditions. The microstructures of the alloy in both states consist of the spherical αp phase, acicular αs phase, and a small amount of β phase. Attributed to such heterogeneous microstructures, the hot-rolled alloy exhibits an outstanding tensile strength of 1046.1 MPa, a total elongation of ~8.3%, and an impressive low density of 4.23 g/cm3. After heat treatment, the alloy also exhibits a similar strength and ductility. A detailed analysis of the deformation modes shows that the numerous dislocations slippages and deformation twinning in the αp phase are the main reasons for the high ductility, and the acicular αs phase provides the alloy with high strength after heat treatment. This newly developed alloy is a potential material for various structural applications.