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Rheological investigation of mim feedstocks prepared with different particle sizes

M. Amin, Sri Yulis and Muhamad, Norhamidi and Jamaludin, Khairur Rijal and Abdullah, Shahrir and Ab. Rahman, Mohd Nizam (2007) Rheological investigation of mim feedstocks prepared with different particle sizes. In: World Engineering Congress 2007, 5-9 August 2007, Pulau Pinang, Malaysia.



size of 16 and 31µm, mixed with PMMA, PEG and stearic acid as a binder at 63% of volume. The viscosity and shear rate of the feedstocks were measured via capillary rheometer across L/D=10 capillary die at constant temperature of 130oC. Through the analysis, all feedstocks showed significant pseudo plastic behavior as the flow behavior index, (n) was less than one. Moreover, the flow behavior index of the coarse powder was larger than the fine powder particles. The activation energy, E of each feedstock demonstrates the feedstock sensitivity to the temperature and pressure. The E value was inversely proportional to the shear rate and still higher at coarser powder. The moldability parameter, α for each feedstock was also significant, and the value was decreased when smaller particle size was used. The results indicated that the feedstock containing larger particle size (31µm) displayed the best rheological behavior with the highest moldability parameter, α. However, this feedstock showed high sensitivity to temperature fluctuations; thus, it will possibly freeze in the mold cavity at a wide range of temperature, besides maximizing stress concentration, cracks and shape distortion.

Item Type:Conference or Workshop Item (Paper)
Additional Information:World Engineering Congress 2007 (2007 : Penang, Malaysia); ISBN 978-983-43571-0-8
Uncontrolled Keywords:metal injection molding, rheology, particle size, feedstocks
Subjects:T Technology > TJ Mechanical engineering and machinery
Divisions:Mechanical Engineering
ID Code:5667
Deposited By: Khairur Rijal Jamaludin
Deposited On:23 Jun 2008 00:24
Last Modified:01 Jun 2010 15:33

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