Characterization of Particle Packing in an Injected Molded Green Body

Abstract

The particle packing structure of alumina green bodies made by injection molding has been examined with the liquid immersion technique coupled with a polarized light microscope. In this method, the specimen is made transparent by an immersion liquid and is examined in the transmission mode. Fine particles of near‐equiaxed alumina powder are found to be aligned, with their slightly elongated axis parallel to the flow direction of the molding process. The presence of very large alumina particles was also noted. Their concentraton was extremely low and can be detected only by the present method. The origins and significance of particle orientaton and large particles in ceramic processing are discussed.