Flow Properties of Al2O3 Ceramic Injection Moulding Feedstocks - Rheological Characterization using Master Flow Description

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F20%3A63527074" target="_blank" >RIV/70883521:28110/20:63527074 - isvavai.cz</a>

Alternative codes found

RIV/70883521:28610/20:63527074

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Flow Properties of Al2O3 Ceramic Injection Moulding Feedstocks - Rheological Characterization using Master Flow Description

Original language description

One of the crucial inputs in PIM (Powder Injection Moulding) is an appropriate flowability of the processed material called a feedstock. PIM is composed of four consecutive steps: preparation (mixing) of a feedstock, injection moulding, debinding, and sintering. To ensure a good quality (with no porosity) of the final products after the final step -sintering- it is inevitable to prepare high density mixture, in this case 52 vol. % loading of submicrometric Al2O3 ceramic particles with a correspondingly high specific surface area. Three different binders were used with participation of stearic acid as a surfactant contributing to better flowability of the whole feedstock. The classical trial-and-error method to optimise quality of the final products is very time-consuming and expensive. At present this method is successfully substituted by a simulation approach. However, efficiency of this approach strongly subjects to well-defined entry characteristics. One of these is represented by a suitable description of a feedstock viscosity. With the onset of new materials and new processing conditions (such as high packaging) the traditionally applied classical constitutive models (relating viscosity with an exerted deformation) are no longer applicable and there appears a necessity of finding new ways. In this case we decided to derive master curves for a viscosity description (individually for each out of 3 binders). Each master curves depends only on volumetric concentration of the surfactant (stearic acid) and does not depend on any other parameter. By this way we obtain sufficiently smooth continuous description of viscosity depending on a rate of shear deformation and a volumetric content of stearic acid component. An inaccuracy does not exceed the experimental errors in measuring shear viscosity of all 3 feedstocks.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20302 - Applied mechanics

Project

<a href="/en/project/LO1504" target="_blank" >LO1504: Centre of Polymer Systems Plus</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2020

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů