氧化钙对锆酸钡陶瓷型芯性能的影响OA

Ceramic core is the key material of preparing hollow turbine blade,and its performance affects the quality and yield of the blade.At present,the existing silica and alumina ceramic cores cannot meet the requirements of casting alloy blades at higher temperatures,it is urgent to develop new system of ceramic cores.In this study,the ceramic cores based on barium zirconate were prepared,and the effects of calcium oxide content and sintering temperature on the structure,mechanical properties and leachability of the barium zirconate-calcium oxide composite cores were explored.The results show that,at a certain sintering temperature,with the increase of calcium oxide content,the core weight loss rate increases,the porosity first increases and then decreases,and the bulk density and the flexural strength first decrease and then increase.Sintering temperature has a relatively minor effect on the mass loss of the core,with the increase of sintering temperature,the porosity decreases,and the bulk density and the flexural strength increase.The core removal rate decreases with the increase of sintering temperature,and the addition of CaO can reduce the removal rate,too.Through comprehensive analysis,when the calcium oxide content is 10%and the sintering temperature is 1 600℃,the barium zirconate-calcium oxide composite ceramic core material exhibits relatively excellent properties,with sintering weight loss rate of 4.22%,porosity of 12.1%,bulk density of 4.72 g/cm3,and the flexural strength can reach 66.15 MPa.