Investigation of microstructural evolution of gas-assisted metal injection molded and sintered Mg-0.5Ca alloy

Abstract

In this study, Mg-0.5Ca alloy was produced in a newly designed unit during the metal injection molding process. 40?mD90 Mg powder and 500nmD90 Ca powder were used in accordance with injection molding and powder sintering rules. In the injection phase, Polyethylene-glycol (PEG) and Poly-methyl-methacrylate (PMMA) and stearic acid (SA) polymers act as binders and lubricants. In the experimental phase, X-ray Diffractometer (XRD), Thermal Gravimetric Analyze (TGA), Scanning Electron Microscope (SEM) equipped with Energy Dispersive Spectroscopy Mapping (EDS and MAP), and Vickers microhardness (HV) examinations were performed. The samples produced were subjected to the sintering process at different temperatures and times. Conventional powder sinter stages point, neck, and joining structures were obtained at different temperatures and durations. As a result, it was determined that Mg-0.5Ca alloy reached a metallic form with the specified polymer structure only at 600oC temperature and after 5 h sintering. Grain boundaries were formed in the sintered sample and the presence of the Mg2Ca phase was observed. The hardness of the metallic structure obtained was measured as 49.9 HV0.1 on average.