No abstract

No abstract

No abstract

In this study, we describe a novel method for preparing Y2O3@CaO ceramic cores with anti-hydration performance and high-interface stability against interface reaction of Ti–6Al–4V alloys. The effect of Y2O3 coating on microstructure, mechanical, anti-hydration properties of ceramic cores and interface reaction with Ti–6Al–4V alloys was studied. The results show that the surface charge of Y2O3 and CaO are opposite at the pH value of 13, which might result in an electrostatic force and become the main driving force of Y2O3 particles absorb on the surface of CaO particles. The Y2O3 coating improved the anti-hydration properties of the CaO-based ceramic cores after sintering at 1450 °C. Meanwhile, the flexural strength improved from 11.2 to 18.8 MPa. At last, the interaction between the ceramic cores and Ti–6Al–4V metal were studied by centrifugal investment casting. Y2O3 coating can effectively reduce the interface reaction and the thickness of the interaction layer in the casting was less than 10 μm. The results suggest that the Y2O3@CaO ceramic with anti-hydration performance provide excellent mechanical and high-interface stability against interface reaction of Ti–6Al–4V alloys.

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.