Design Strategy and Strengthening Mechanisms of A Novel Ultra-Hard Titanium-Based Alloy

Titanium (Ti) is widely used in the aerospace industry, however, its degradation of mechanical properties and oxidation resistance at high temperatures and the low machinability limit its application. Recent strategies to enhance Ti-based alloys include the strategic integration of thermally stable alloying elements and advances in fabrication techniques. In this study, a novel Ti-W-Fe alloy system was designed and fabricated via hot-press sintering. The sintered Ti-W-Fe alloy exhibits a homogenized ultra-fine grained microstructure with metastable phases, including FCC-Ti and Ti2Fe formed during the plastic deformation stage of sintering. These phases contribute to the exceptionally high hardness and elastic modulus of the alloy, compared to the existing Ti-based alloys. Furthermore, the Ti-W-Fe alloy demonstrates excellent thermal stability, suggesting the potential for ideal high-temperature mechanical properties. High Angular Resolution EBSD (HR-EBSD) analysis confirmed that the Ti-W-Fe alloy possesses a fine-scale, homogeneous distribution of geometrically necessary dislocations (GNDs) and negligible residual stresses, indicating that the applied processing route successfully stabilizes the microstructure and enhances mechanical uniformity. This novel Ti-W-Fe alloy system holds significant prospects in aircraft engineering applications subjected to extreme conditions.