The uses and applications of hydrogen processing for titanium additive manufacturing

^a United States Army Research Laboratory, 4600 Rodman Rd., FCDD-RLW-MF Aberdeen Proving Ground, Maryland 21005, USA
^b Department of Metallurgical Engineering, the University of Utah, 135 South 1460 East Room 412, Salt Lake City, Utah 84112, USA

^* Cooresponding Author: matthew.k.dunstan.ctr@mail.mil; mkdunstan10@gmail.com

Abstract

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.