Rheological Analysis of Microminiature Powder Injection Molding (μPIM) Feedstock

Abstract:

A rheological analysis has been performed to evaluate the characteristics and behaviors of Microminiature Powder Injection Molding (μPIM) feedstocks. The feedstocks comprised of 316L stainless steel powder and water-based binder components. Feedstocks formulations with powder loading of 59% to 63% were prepared and investigated. In these formulations, the binder system consists of 65% Polyethelena Glycol (PEG), 25% Polymethyl Methacrilate (PMMA) and 10% Cellulose Acetate Butyrate (CAB) based on the weight fraction. The influences of rheological behaviors such as flow activation energy (E), Power-Law exponent (n), viscosity (η) and temperature (T) of the SS316L/PEG/PMMA/CAB feedstocks are analyzed and discussed. Results show that all of the feedstocks exhibited the pseudo-plastic flow behavior. The homogenous feedstock at 61 vol. % demonstrated the most satisfactory rheological properties for μPIM with the lowest flow activation energy, Power-Law exponent, n < 1 and moderate viscosity values. It was chosen to perform the injection molding process. Micro components have been replicated successfully by using this selected feedstock.

• Periodical: Applied Mechanics and Materials (Volumes 52-54)
• Pages: 238-243
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.52-54.238
• Online since: March 2011
• Authors: Haw Pei Li, Norhamidi Muhamad
• Keywords: Feedstock, Microminiature Powder Injection Molding (μPIM), Pseudo-Plastic, Rheological Analysis

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DOI: 10.1016/j.matchar.2004.11.014