Improving spreadability of hydrogenation-dehydrogenation Ti powder via surface treatment using silane-based compounds

Ti powder is manufactured using several methods such as sponge screening, hydrogenation-dehydrogenation (HDH), and atomization. Manufacturing of Ti powder using HDH process is approximately 70% less expensive than that using gas atomization. The irregularly shaped particles of Ti powder fabricated using the HDH process have a lower spreadability than the spherical particles of Ti powder produced using atomization. Hence, HDH Ti powder cannot be used in powder bed fusion (PBF) method, which is an additive manufacturing process. Therefore, in this study, the spreadability of HDH Ti powder was improved by changing the powder surface from hydrophilic to hydrophobic using silane-based chemicals. The flowability, shape, and purity of the surfacetreated Ti powder were analyzed, and the surface bonding characteristics of the powder were studied using Xray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. The hydrophobic modification was confirmed by measuring the contact angle of the powder with water. For evaluating the improvement in spreadability of the powder, a recoating tester with the actual PBF driving method was created. The results indicated that the proposed method can be used in additive manufacturing and can reduce the cost of HDH Ti powder while improving the spreadability of the powder particles.