A numerical model to predict the powder–binder separation during micro‐powder injection molding

Abstract

The micro‐powder injection molding (micro‐PIM) process has the potential to bridge the gap between the design and manufacturing of micro‐components that are often used in small and handy devices. Numerical modeling helps to analyze and overcome various difficulties of micro‐PIM. In the present work, a numerical model is developed to predict the powder–binder separation (a common defect in PIM and especially severe in micro‐PIM) during the injection of an alumina feedstock. A powder–binder separation criterion is proposed dealing with applied injection pressure and friction force between the powder and binder. An indirect comparison of feedstock travel time between two locations is used to validate the model. The predicted segregation from the simulated result is supported by a qualitative experimental measurement. The developed model can be used to optimize injection parameters to get a defect‐free product.

Moldflow Simulation and Characterization of Pure Copper Fabricated via Metal Injection Molding

“…To alleviate the aforementioned problems, the injection gate was positioned so that it was pointed from the C part toward the B part as shown in Figure 2b. According to the proposed model about the influence of filling patterns on the powder-binder separation in powder injection molding, it was likely that binder separation would occur toward the side the gate pointed to [38][39][40]. Accordingly, the gate position used in this study was placed so that it pointed toward the A part, which would intentionally direct the unavoidable powder-binder separation to the end of the A part.…”

Micro-Injection Molding and Debinding Behavior of Hydroxyapatite/Zirconia Bi-Materials Fabricated by Two-Component Micro-Powder Injection Molding Process

“…The significance of the mass production of intricately downsized or micro-structured components has intensified in recent years. Micro-powder injection molding (µPIM), which is a modification of the powder injection molding (PIM) process, is a financially viable method of processing materials for the fabrication of ceramic and metallic micro-sized components [1][2][3]. Similarly to PIM, the µPIM process offers several advantages such as low production cost, excellent surface finishes, nominal post-production scrap, and outstanding mechanical properties [4][5][6][7][8][9].…”