Effect of Particle size on SLS and post-processing of Alumina with Polymer binders

Alumina powders with mean particle size of 15 J.lm, 2 J.lm and 0.5 J.lm were processed by SLS using polymer binders. The 2 J.lffi and 0.5 J.lm powders were given a thermal agglomeration treatment before SLS. The green shapes after SLS were infiltrated with a colloid of aluminum oxide. After infiltration the samples were given suitable heat-treatment to remove the polymer binder by thermal decomposition followed by a sintering treatment at 16OOC. Green densities were in the range of 45% of theoretical density for the agglomerates of 2 Jlm and 0.5 J.lffi powders while it was about 36% of theoretical density for the 15 J.lffi powders. Sintered densities were about 55% of theoretical density for the samples from agglomerates of 2 J.lffi and 0.5 Jlm powders while it was 42% of theoretical density for the samples from 15 J.lm powders. The strength of samples were measured in the green state and after sintering to determine the effect of particle size.