Mechanical properties of dry-pressed alumina green bodies

The elastic modulus and the tensile strength of uniaxially pressed alumina-kaolin green bodies were measured using noncontact ultrasound and diametral compression, respectively, These properties showed a strong dependence on the green density and, therefore, the compaction stress. The dependence on density was compared with theoretical models and these did not accurately describe the observed behavior. Possible causes of the discrepancies with the theoretical derivations are discussed. The choice of binder was shown to play a critical role in determining the elastic modulus, strength, strength variability, and fracture morphology.