Development of a Starch-Based Binder in Metal Injection Molding

Abstract:

A new starch-based binder as a natural polymer has been developed for metal injection molding (MIM). In this study tapioca starch which is cheap and readily available in Malaysia has been used as a binder which composed of starch, glycerol, linear low density polyethylene (LLDPE), citric acid and stearic acid. This developed binder system was mixed with 316 L stainless steel powder to prepare the feedstock at three different of powder loadings of 56, 57 and 58% vol. The rheological behavior of the binder and feedstock were evaluated at different temperatures using a capillary rheometer. The rheological behavior of binder shows less than 10 Pa s and the flow behavior index of the feedstocks were determined to less than 1, which indicates the flow characteristic is pseudo-plastic which is suitable for MIM process. Finally, among these three feedstocks, the feedstock of 57% vol. powder loading was selected and its viscosity values within expected shear rate range are less than 1000 Pa s.

• Periodical: Advanced Materials Research (Volumes 83-86)
• Pages: 24-30
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.83-86.24
• Online since: December 2009
• Authors: Norhamidi Muhamad, Hooman Abolhasani
• Keywords: Binder, Feedstock, Metal Injection Molding (MIM), Rheology

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