Study On The Preparation Technology Of Alumina Ceramic For Turbine Blade Casting

The gel casting technique for the preparation of alumina ceramics is reviewed in this paper.Its princple is put organic monomers and cross-linking into the deionized water,then add the alumina powder materials,under the effect of initiator and catalyst,organic monomers and cross-linking of the low viscosity and high solid content of slurry reacted,which could be caused the polymerization and made the slurry in-situ formation.Based on this process,the paper studies the gel casting technique for the preparation of alumina ceramics and the performance of the alumina ceramics through experiment.The paper studies preparation of alumina ceramic slurry,the experimental materials including different particle sizes of alumina powder,organic monomer,cross-linking,MgO and Y2O3,etc.The critical point is to obtain the influence factors on the viscosity of alumina ceramics slurry.It also studies the influential rules of ratio of thick and thin corundum powder on viscosity of the ceramic slurry.The effect of solid content,dispersant,pH and the ball milling time to the fluidity is discussed in the thesis.The result shows that alumina slurry of 55%in solid content with a low viscosity is obtained by adding 2wt%dispersant,2 hours ball milling time,and PH value of 9.The paper also studies the process of dryness,degumming and sintering and the effect of catalyst,initiator and temperature on the gelation time,there is 10-25 min remained for slurry casting.Drying process and sintering process of ceramic were determined through the experimental comparison.The effect of solid content on drying and sintering shrinkage,the influence of solid content on body strength was analyzed through experiment.Finally,performance testing on sample of sintered alumina ceramic was carried out,microstructure observation and analysis on the sample of sintered alumina ceramic was made by micro scanning technology.