Determination of an Effective Viscosity of Powders as a Function of Temperature
A method is described for determining the effective viscosity of powder compacts during densification as a function of temperature. The method utilizes constant rate of heating and is easily adapted to determining the sintering temperature of a powder compact as well as measuring the effective viscosity. The method can be used for crystalline as well as glassy (amorphous) systems. Values of the coefficient of viscosity or diffusion can be determined for powders of simple particle geometry and known particle size distribution. For practical applications, an effective viscosity is proposed as a better measure of densification characteristics. Illustration of the method is made by examining shrinkage characteristics of various ceramic powder compacts at constant rates of heating.
KeywordsPowder Compact Boundary Diffusion Effective Viscosity Volume Diffusion Glass Powder
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