A basic study on metal foam fabrication with titanium hydride in direct energy deposition

Direct energy deposition (DED) is one of additive manufacturing processes, which achieves high production efficiency by supplying material powder and irradiating high-power laser beam to a baseplate at the same time. Furthermore, the DED has a potential to produce a functional material by blending various material powders. Although a metal foam structure is well-known because of its beneficial functionality such as light-weight, the complicated foaming process requires a special equipment and long processing time. This paper proposes a simple fabrication method for metal foam structure by applying a blowing agent into DED. Metal foam structure can be produced by foaming the meltpool with titanium hydride which releases hydrogen in a high temperature environment. The proposed method certainly produces a foam structure in stainless steel by blending titanium hydride powder into stainless powder for DED.