Research On Gel Forming Process And Surface Quality Of The Ceramic Casting Mold For The Hollow Turbine Blades

The integral ceramic mold preparation technique based on rapid prototyping provides anew solution for solving the manufacturing problems of hollow turbine blades. To acquire theintegral ceramic mold for hollow turbine blades which have the integrated structures and highperformances, this article focuses on some research of casting ceramic slurry, and formingprocesses and casting surface quality of vacuum injection mold.This paper studies the preparation methods of ceramic mold’s slurry for hollow turbineblades. Given that ceramic mold’s forming ability and calcining ability, it is determined thatthe matrix material is fused corundum, and the mineralizer are magnesium oxide andnano-yttria. Experiments study the influential rules of ratio of thick corundum powder andthin corundum powder on the ceramic slurry’s fluidity, the casting mold shrinkage and thehigh-temperature mechanical properties, and decide the optimal ratio of thick corundumpowder and thin corundum powder. After experiments that how the content of organicmonomers has an influence on gel injection mold process, it ac hieves the rational adjustmentof the content of organic monomers in ceramic slurry. The dissertation designs a orthogonaltable of L9(34),and proceeds to do some research for orthogonal experiments of slurry’srheological property. The result of experiments shows that ceramic slurry which has a lowviscosity and a good fluidity will be made on condition of3wt%dispersing agent, an hourball milling time, and PH value of9.Vacuum dynamic injection mold’s process parameters of ceramic casting mold for hollowturbine blades are studied. As for the amount of evaporating water in the slurry, advisablevacuum value(-0.09MPa) are laid down, combining with the vacuum degree,which ensurethe validity of vacuum injection mold. How a curing agent and temperature have an influenceon the gel reaction are researched, and determining the adding amount of initiators APS to be0.6wt%, the adding amount of catalyst TEMED to be0.05wt%and the temperature to be25℃can realize the controllable curing of vacuum injection mold. The results of research on filling capacities for ceramic slurry using a homemadestandard model which has the shape of U demonstrates that ceramic slurry adopting thisprocess completely satisfies the requirements of injection mold. Process paramete rs of thevacuum casting are also defined, which are as follows: casting temperature is25℃, vibrationamplitude is1mm~3mm and vibration frequency is30~60HZ adopting the physical field ofvibration. The experiment researches the influences which process parameters have on theperformance of ceramic casting mold, and the results manifest that adapting vacuum dynamicforming process has a greater improvement for the intensity of green bodies and sinteredbodies.The methods of improving casting mold’s surface quality are researched in this article.The reasons for affecting ceramic casting mold to generate scarfskin are analyzed, and theways to ameliorate the surface quality of casting mold using coating are also exploringlystudied, and the results are analyzed as well. but the results was not satisfied. Research for howheating rate influences the casting mold’s surface quality within the temperature rang of300℃~450℃shows that the phenomenon of generating scarfskin can be effectively avoidedwith the heating rate of15℃.