Development of High Strength Ti-Cu based alloys with Equiaxed Grain Growth Produced via Plasma Metal Deposition

The growing demand for titanium alloys, particularly in the aerospace industry, arises from their remarkable strength-to-weight ratio. However, the commonly used Ti-6Al-4V (Ti64) alloy exhibits columnar grain growth after additive manufacturing, such as powder bed fusion or direct energy deposition, resulting in anisotropic mechanical properties. To overcome this, Ti-Cu-based alloys are introduced for equiaxed grain growth, but their mechanical properties fell short of Ti64. \n Ternary and quaternary alloying elements (Fe and Cr) are incorporated to enhance mechanical properties. Firstly, several alloys (Ti-6.5Cu-xCr-yFe) produced via powder hot-extrusion exhibit promising microstructure under light microscopy and SEM. Hardness and tensile strength are improved, even exceeding the tensile strength of Ti64. \n The most promising ones underwent the blown-powder Plasma Metal Deposition process for in-situ alloying, revealing fine microstructures, equiaxed grains, and increased tensile strength. These findings highlight their potential for aerospace applications, presenting isotropic mechanical properties and dense samples.