Preparation of SiC-based composites by cold isostatic press

Abstract

The effect of polyvinyl alcohol binder on green strength of isostatic pressed silicon carbide was studied. A lab-top spray dryer was used to coat mixed powders with the binder. The resultant powders were pressed in a steel die to obtain pre-mold at the compaction pressures of 32, 63.5, 127, 190, 254 and 317 MPa. The pre-molds were pressed using a cold isostatic press at 276 MPa to produce the green compact specimens. The porosities and compression stress of the green compact specimens produced from laboratory powder were compared with compacted specimens produced with commercial powder. Density porosimetry and universal testing machine were used to determine porosity and compression stress; respectively. The morphology and fracture surface of the green compact specimens were observed under optical and electron microscopes.