Influence of powder particle size on microstructure and performance of calcium oxide based ceramic core

A calcium oxide (CaO) based ceramic core used for titanium alloy casting was prepared by injection moulding technology. Through quantitative characterisation and statistical analysis of the microstructure, the influence of powder particle size on the microstructure and properties of the ceramic core was investigated. The results show that, by increasing powder particle size, the size of pores and porosities after sintering were increased with decreased of grain boundary density. Meanwhile, the flexural strength of ceramic core at room temperature was found to decrease with increasing core porosity, and the creep resistance of ceramic core increased with decreasing grain boundary density. The increase in powder particle size of ceramic core is beneficial to reduce linear shrinkage and improve high temperature creep resistance.