Effect of the Process Parameters on the Mechanical Properties of Hinge Component Made of Superhard Alloy Powder Injection Molding(1/2)

Metal injection molding (MIM) is a widely used manufacturing process of complex-shaped products, such as the hinge component in laptop. Compare with the casting and forging processes, the standard material of MIM has less hardness than that of casting/forging process. The aim of this proposal is thus to evaluate the feasibility of applying the superhard alloy powder to MIM through a modified prescription of feedstock. Furthermore, effects of injection parameters and sintering temperature on the mechanical performance of end product will be investigated. In order to ensure the quality of MIM alloy, its microstructure variations will be observed through the microscope.This experiment may utilize the gas atomization to produce the Mo2FeB2 or NiB powder. The powder is then custom formulated with BASF Catamold® 4605 and POM-based binder into a feedstock via kneading and granulating. The feedstock is injected as a melted liquid into a mold using plastic injection machines. After cooling, the green part is ejected from the mold. Subsequently, most of the binder is extracted using a catalytic debinding process, resulting in the brown part. Finally, the brown part is transferred into the sintering furnace under a controlled atmosphere. The objective of this experiment is to improve the hardness and the strength of end-product metal through feedstock preparation and temperature control sintering. The strengthening mechanism of MIM alloy will be investigated through the analysis of microstructure.In this proposal, not only will the injection molding experiment be carried out, but the CAE analyses will also be developed to help the mold design and understand the flow behavior of powder-binder mixtures. Injection parameters such as melt temperature, mold temperature, injection speed, etc. will be investigated their influence on the end-product characteristics and qualities. Rheological and thermal properties of melted feedstock will be measured for accurate CAE simulation. It is expected that the defect of powder-binder separating, uniform shrinkage, stable quality and productivity can be greatly improved. Ultimately, this methodology may serve as a reference for manufacturing hinge components having mechanical properties according to MPIF Standard 35.