The superplastic behavior of powder injection molded blends

碩士 === 國立臺灣科技大學 === 機械工程研究所 === 83 === Powder injection molding is a novel process in use in the powder metallurgy industry which comprise a metal or ceramic powder and binder agent, there are intrinsic limitations with these processes, such as :difficult...

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Bibliographic Details
Main Authors: Szu-Chih, Liu, 劉思治
Other Authors: S. T. Lin
Format: Others
Language:zh-TW
Published: 1995
Online Access:http://ndltd.ncl.edu.tw/handle/55190018581110766422
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Summary:碩士 === 國立臺灣科技大學 === 機械工程研究所 === 83 === Powder injection molding is a novel process in use in the powder metallurgy industry which comprise a metal or ceramic powder and binder agent, there are intrinsic limitations with these processes, such as :difficulties in forming intricate, thin and irregularly shaped parts because the feedstock has inadequate flow properties which lead to density variations or entraped air in the part, cause shrinkage and distortion during debinding. The binder systems were added to the variation powder-binder formulation. The effect of the binder system on the flow properties, melting and adsorption behavior, forming and thermal history characteristic of the formulation was investigated by capillary rheometry, thermal analyzer, zeta potential analyzer, infrared spectroscopy studies. Specific binder formulation which contains functional group polymers can easily create the mono layer coverage on the powder surface, adsorption isotherm with a small amount of binder, consequently increasing the solid loading of powder-binder blend. The blends exhibited a flow pattern similar to a Newtonian fluid with a low activative energy of flow. During 170℃ ,the blends could be drawn from 3 mm in diameter down to less than 0.1 mm, such a superplastic phenomenon was attributed to a strong interfacial adhesion between powder and binder arising from the surface agent on to the Powder binder blends.