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.
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