Optimizing Ceramic Preform Properties for Liquid Metal Infiltration

In this paper, a methodology to optimize the production technique and properties of fly ash porous preforms, for liquid metal infiltration, is introduced. The preforms were produced by mixing fly ash with acid phosphate binder and acetone as liquid carrier, at varying compositions. The homogeneity of the green product was determined by micro computed tomography (μCT) and scanning electron microscopy. The effect of binder quantity, porosity, and compaction pressure of the preforms on the resulting bending strength was investigated and considered as one of the criterions for the production of crack-free metal matrix composites (MMCs). Finally the quality of the MMCs, resulting by liquid metal infiltration of the optimized preforms, was examined by μCT to locate micro cracks and uniaxial compression to determine variations in their compressive strength.