Influence of powder loading on densification and microstructure of injection molded Fe-50Ni soft magnetic alloys

Metal injection molding (MIM) is a well-known technique capable to produce micro size electromagnetic components with intricate shape features. Powder loading is a crucial parameter in the metal injection molding process which controls the densification and microstructure of the sintered parts. The lower powder loading leads to various defects and lower densification whereas higher loading results in failure of parts during injection molding. Therefore, it is important to engineer an appropriate powder loading to achieve defect-free parts along with higher densification and improved microstructure. In this contest, three feedstocks of Fe-50Ni alloys are prepared with powder loadings of 52 vol.%, 54 vol.% and 57 vol.% and injection molded. After debinding, the parts are sintered at 1325 degrees C for 2 h. The main objective of this study is to investigate the effect of powder loading on injection molding, densification, and microstructure. In addition, scanning electron microscopy and x-ray diffraction analysis are performed during the study. The defect-free green parts are produced successfully from the 52 % and 54 % loading. It has been found that the optimal powder loading of 54 % is the best from the perspective of enhanced densification and improved microstructure to assure the quality parts of Fe-50Ni alloys via metal injection molding.