Design and preparation of gel-casting ceramic slurry for gas turbine blades

To obtain the ceramic slurry with low viscosity,good fluidity and high solid content,cylinder rotating viscometer was used to measure apparent viscosity of different bimodal alumina ceramic slurry,and the influences of powder particle size,shape and grade ratio on slurry fluidity and solid content were studied.The results show that large powder particle size ratio,regular sphere and large distribution of particle size make it more convenient to fabricate ceramic slurry with low viscosity and high solid content.The ceramic slurry with apparent viscosity of 0.411 Pa·s,solid loading of 63% was successfully prepared,which could fully fill a jet hole cooling structure with the diameter of 0.7 mm.The strength of the ceramic mold is bigger than 18 MPa under 1 300 ℃,with shrinkage after sintering less than 1%.