Mechanical and corrosion properties of full liquid phase sintered WE43 magnesium alloy specimens fabricated via binder jetting additive manufacturing

Abstract

This study investigates full liquid phase sintering as a process of fabrication parts from WE43 (Mg-4wt.%Y-3wt.%RE-0.7wt.%Zr) alloy using binder jetting additive manufacturing (BJAM). This fabrication process is being developed for use in producing structural or biomedical devices. Specifically, this study focused on achieving a near-dense microstructure with WE43 Mg alloy while substantially reducing the duration of sintering post-processing after BJAM part rendering. The optimal process resulted in microstructure with 2.5% porosity and significantly reduced sintering time. The improved sintering can be explained by the presence of Y2O3 and Nd2O3 oxide layers, which form spontaneously on the surface of WE43 powder used in BJAM. These layers appear to be crucial in preventing shape distortion of the resulting samples and in enabling the development of sintering necks, particularly under sintering conditions exceeding the liquidus temperature of WE43 alloy. Sintered WE43 specimens rendered by BJAM achieved significant improvement in both corrosion resistance and mechanical properties through reduced porosity levels related to the sintering time.

Keywords

• Magnesium alloy
• Liquid phase sintering
• Additive manufacturing
• Binder jetting process
• Biodegradation