Re. Dutton et al., MODELING THE HOT CONSOLIDATION OF CERAMIC AND METAL POWDERS, Metallurgical and materials transactions. A, Physical metallurgy andmaterials science, 26(8), 1995, pp. 2041-2051
Modeling of the consolidation of ceramic and metal powders by sinterin
g, hot pressing, and hot-isostatic pressing (HIP) was conducted using
a continuum yield function and associated-flow rule modified to incorp
orate microstructure effects such as grain growth, pore size, and pore
geometry. It was shown that consolidation behavior can be described o
ver the entire range of densities through two parameters, the stress i
ntensification factor and Poisson's ratio, which are readily measured
using uniaxial upset tests. Both parameters are functions of relative
density, whose exact dependence varies from one material to another. F
urthermore, it was demonstrated that in sinter forging of ceramics, an
''apparent'' Poisson's ratio depending on stress level (relative to t
he sintering stress) gives a quantitative measure of the competition b
etween sintering and creep deformation. The accuracy of the microstruc
ture-sensitive yield function was established through finite-element m
odeling (FEM) simulations of the isothermal sintering of a soda-lime g
lass, sinter forging of alumina, and die pressing of an alpha-two tita
nium aluminide alloy.