烧结温度对SiO_2-ZrO_2体系陶瓷型芯材料性能影响研究

Effect of Sintering Temperature on Ceramic Cores Performances of SiO_2-ZrO_2 system

采用传统的热压铸工艺制备可快速脱芯的定向、单晶空心涡轮叶片用S iO2-ZrO2体系陶瓷型芯材料,研究结果表明,该材料随烧结温度从1150℃增加到1200℃,收缩率变大,当烧结温度超过1200℃时,烧结收缩增加显著,1200℃烧结的陶瓷型芯晶粒发育比较完善,主要相组成为非晶S iO2、方石英、ZrO2,其综合性能最佳,室温强度可达42.9 MPa,1550℃具有较好的抗高温变形性和优异的高温强度,高温变形为0.1mm,高温强度可达27.9MPa,开气孔率可达30.4%,体积密度为1.92g/cm3,烧结收缩率仅为0.4%,方石英析出量20%左右,能够满足我国航空发动机高温合金空心涡轮叶片的浇注要求。

The easy leachable SiO2-ZrO2 ceramic cores used in directional solidification and single crystal hollow blades were prepared by traditional hot-pressure casting.The results show that the a sintering shrinkage increased with the increasing sintering temperature from 1150℃ to 1250℃,and sintering shrinkage is increased markedly above 1200℃.Well-grown crystalline grains were shown,and main compositions are composed with non-crystal silica,cristobalite and zirconia.The material properties sintering at 1200℃ are optimized,and bending strengths reach 42.9MPa,and best anti-deformation and bending strengths are also obtained at 1550℃.High temperature anti-deformation is 0.1mm,and the high temperature bending strength,pore,densiy and sintering shrinkage are 27.9MPa,30.4%,1.92g/cm3 and 0.4% respectively.The formations of cristobalite is about 20%.It meets the pouring requirement for superallay hollow turbine blades of the aero-engine.