5:55 PM - 6:15 PM
[15A-T7-09] Pressureless Mg Melt Infiltration into Ti Powder Preform with Various Flow Channel Structures toward the Application to Binder Jetting Additive Manufacturing
Keywords:Additive manufacturing, Pressureless melt infiltration, Relative density, Capillary force, Computed tomography
Binder jetting (BJT), an additive manufacturing process, injects a binder to the powder bed to build up the green body. The green body undergoes sintering to obtain a dense product. However, the shrinkage during sintering makes it difficult to achieve a high dimensional accuracy. Pressureless melt infiltration (PMI) is an alternative process that fills the pores of a preform with a metal melt spontaneously infiltrating by the capillary force. It becomes important to clarify how molten metal infiltrates and how defects form. This study investigates the mechanism of defect forming inside PMIed Mg/Ti composites by controlling the structure of Ti powder preforms. Different-sized (20-2300 μm) and shaped (irregular and spherical) Ti powders were pressed under various pressures (76-178 MPa) to fabricate preforms with various structures. It was found that the flow channel radius and the presence of “pocket structure” were key factors for defect formation in the composite.