Powder Characteristics Influencing Density Distribution in Green Pellet

Abstract

Density distribution in green pellets of many kinds of Al₂O₃ powders was evaluated by energy dispersive X-ray analysis and calculations using a finite element method. Calculated density distributions agreed well with experimental results. Density homogeneity in green pellet has a distinct correlation with a material constant, n, defined in the following yield function.
ρ²ⁿB²=((σ₁, -σ₂)²+(σ₂-σ₃)²+(σ₃-σ₁)²)/2+A²(l-ρ)^2mσ²_m
where ρ is relative green density, σ_i is normal stress, σ_m is mean normal stress and B, A, in are material constants.