Effect of EPS Porogen on Microstructure and Properties of ZTAp/High Chromium Cast Iron Composites

The expandable polystyrene was added to the gap in the ceramic preform which was made of ZrO₂ toughened Al₂O₃ (ZTA) ceramic particles. Increasing the porosity of the preform is beneficial to the high chromium cast iron infiltration and can obtain the composites of ZTA particles reinforced high chromium cast iron matrix. In this paper, studied the residues amount of the different porogen in the preform such as 10 ~ 20 mesh, 20 ~ 40 mesh, 40 ~ 80 mesh, 80 ~ 120 mesh and mixing particle sizes were heated to the temperature of 250, 350, 450, 550 °C. The corresponding composites were obtained under the different conditions and the interfacial effect, the wear resistance of the composites were observed. At the same time, the fracture mode of the composites was analyzed. The results showed that the porosity of preform with mixing particle sizes was the lowest at 550 °C and had the best interfacial, the highest wear resistance. The fracture mode of the composites was the particles fracture, metal matrix brittle fracture and the particles shedding from the matrix.