The uses and applications of hydrogen processing for titanium additive manufacturing

Additive manufacturing has shown to be a promising method for reducing the cost and increasing the complexity of titanium components, with the majority of research focusing on beam-based methods (i.e. powder bed fusion and directed energy deposition). However, these processes produce highly complex thermal histories, which can result in highly anisotropic and otherwise undesirable microstructures and mechanical properties. In an effort to mitigate these challenges, the use of hydrogen as a temporary alloying element has been identified as a promising method to prevent unfavorable microstructures and isotropy in AM Ti-6Al-4V. Herein, the powder metallurgy process known as Hydrogen Sintering Phase Transformation (HSPT) used in conjunction with a solid state AM method known as fused filament fabrication (FFF) is discussed