Enhancing spreadability of hydrogenation-dehydrogenation titanium powder and novel method to characterize powder spreadability for powder bed fusion additive manufacturing

Abstract

A low-cost hydrogenation–dehydrogenation (HDH) Ti powder was employed to reduce the cost of the material used in powder bed fusion (PBF) additive manufacturing. HDH Ti powder was hydrophobic surface-treated with methyltrichlorosilane and mixed with spherical powder at a 1:1 ratio to ensure flowability for PBF process. Subsequently, PBF process with practical recoating speed (50 mm/s) and heat treatment process were optimized. It was confirmed that a high specific strength structural material with interesting mechanical properties at a low cost was formed, with a tensile strength of 924 MPa and an elongation of 9.5 %. This paper also discusses an intuitive and accurate apparatus for measuring the spreadability of metal powders for PBF applications. A recoating tester was developed for direct quantification of the spreadability in PBF, and this confirmed the possibility of using the mixed Ti powder containing low price HDH Ti in PBF with practical recoating speed.

Keywords

• Additive manufacturing
• Powder bed fusion
• Hydrogenation–dehydrogenation titanium powder
• Powder spreadability
• Recoating tester for powder bed fusion