Powder characteristics influencing density distribution in green pellet

摘要

Density distribution in green pellets of many kinds of Al{sub}2O{sub}3 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. ρ{sup}2nB{sup}2 = ((σ{sub}1 - σ {sub}2){sup}2 +(σ{sub}2 - σ {sub}3){sup}2 +(σ{sub}3 -σ{sub}1){sup}2)/2+A{sup}2(1-ρ){sup}2m(σ{sub}m){sup}2 where ρ is relative green density, σ{sub}1 is normal stress, σ{sub}m is mean normal stress and B, A, m are material constants.