A method for improving the high temperature strength of monolithic alumina-based ceramic molds by chemical vapor infiltration

Abstract

The invention discloses a method of improving high-temperature strength of an integral alumina-based ceramic mold through chemical vapor infiltration, and belongs to the field of photocuring forming technology quick casting. The method includes the steps that 1, a resin mold is manufactured through the photocuring quick forming technology; 2, ceramic slurry is poured into a resin mold prototype of turbine blades through a gelcasting method to obtain a cast blank; 3, a porous alumina-based ceramic mold is obtained after vacuum freeze drying and ungrease treatment; 4, the alumina-based ceramic mold is subjected to chemical vapor infiltration, SiO2 generated after pyrolytic reaction of a silicon source precursor and matrix alumina react chemically to generate high-temperature strengthened phase mullite, the pore structure of the mold is filled with SiC generated through the pyrolytic reaction, a functional gradient material with the porosity gradually improved from the surface layer to the core part of the mold, and the porosity of the mold is reduced to improve the high-temperature strength of the mold. The method is reasonable in design and convenient to operate, and the high-temperature strength of the alumina-based ceramic mold is enhanced remarkably.

Description

technical field [0001] The invention belongs to the technical field of rapid casting based on light-curing molding technology, and in particular relates to a method for improving the high-temperature strength of an integral alumina-based ceramic mold through chemical vapor phase infiltration. Background technique [0002] Integral ceramic casting mold rapid manufacturing technology scheme, replacing the traditional core metal mold and "investment mold" with light-cured resin prototype, realizing the integration of core metal mold, "investment mold" structure and function, using gel injection molding The dynamic forming process replaces the ceramic core injection molding process and the coating shell making process, and is widely used in rapid casting, rapid mold and other industries. This method is used to obtain the aluminum oxide-based hollow turbine blade ceramic mold, and then perform metal casting and core removal treatment to obtain the final metal blade. [0003] The...

AI Technical Summary

Problems solved by technology

[0004] At present, there is no report on chemical vapor infiltration in the preparation of ceramic molds. Chemical vapor infiltration is to pass specific element compounds and elemental gases into the reaction chamber where the substrate is placed, and penetrate the surface and interior of the substrate with the help of space gas phase chemical reactions. Process Technology for Solid State Materials