Additive Manufacturing of Mg Alloy Using Directed Laser Energy Deposition: An Investigation into Process Development and Mechanical Properties

摘要

Additive manufacturing (A/M) is a unique emerging technology for enhancing part performance and functionality. Magnesium based alloys are desirable from an A/M perspective because of their low density, biocompatibility and biodegradability. There is limited ongoing research for establishing the feasibility of A/M Mg alloys using both laser powder bed and laser directed energy deposition. These studies have reported limited success due to a combination of challenges presented by the material and powder characteristics. In this study a rare earth containing alloy, Elektron MAP+43, was investigated using directed energy deposition. Parameters such as laser power, scan speed, and chamber oxygen were studied to minimize porosity and obtain as-deposited densities of greater than 99%. A series of rectangular build geometries 7.6cm long × 5.08cm high × 1.27 cm wide and 15.2 cm long × 5.08cm high × 1.27 cm wide were fabricated from which tensile and metallographic samples were extracted and tested from selected orientations. The effects of heat treatment and hot isostatic pressing were also compared. The results showed that the mechanical properties obtained were comparable with that of typical as-cast WE43B alloy and that magnesium alloy powders can be deposited via directed energy deposition.