A kind of preparation method of ceramic core

Abstract

The invention discloses a method for preparing a ceramic core, comprising: 1) drying the ceramic powder at a temperature of 105-140°C; adding it to a vacuum mixing mixer, stirring, and keeping the temperature constant at 75-95°C; 2) .Weigh oleic acid with 0.3-1% of the mass of the ceramic powder, and dissolve it with 10-30 times the volume of absolute ethanol; spray the oleic acid ethanol solution into the ceramic powder, stir, open the outlet valve, fully mix, Exhaust; 3). Weigh the plasticizer with 14-17% of the mass of the ceramic powder, melt the plasticizer and add it to the ceramic powder, and stir thoroughly; 4). Reduce the stirring speed, close the outlet valve, pump When the vacuum is above ‑88kPa, turn off the vacuum pump, resume the stirring speed, and continue to stir until the surface of the ceramic slurry is fine and smooth, without visible bubbles and particles; 5). Transfer the ceramic slurry to the core press machine, stir for more than 8 hours for the ceramic core element The pressing of the billet; molding and roasting the pressed one.

Description

technical field [0001] The invention relates to a method for preparing a precision casting ceramic core. Background technique [0002] In the precision casting process, especially in the near-net-shape investment casting process, the ceramic core is an important transition part to form a hollow casting, which directly determines the structural shape and molding accuracy of the casting cavity. Precision casting has high quality requirements for ceramic cores, and more than 50% of unqualified castings in precision casting are caused by unqualified ceramic cores. The unqualified reasons for ceramic cores are mainly reflected in insufficient flexural strength, poor creep resistance and large shrinkage. [0003] In addition to the physical properties of the material itself, such as chemical composition, particle size distribution, etc., the factors that affect the flexural strength, creep resistance and shrinkage of the ceramic core are the most critical factors that are the pre...

AI Technical Summary

Problems solved by technology

[0005] The firing process is the most critical step affecting the quality of the ceramic core. Defects such as cracks, expansion, deformation, bubbles, peeling, etc., as well as physical properties such as flexural strength and firing shrinkage are closely related to the firing process, and the key to the firing process is It lies in the reasonable and precise control of roasting temperature and roasting time. This technical measure is a commercial secret in the industry and has no way of knowing.

On the other hand, the mechanical and thermodynamic properties of ceramic cores after firing often cannot meet the requirements of use. The common practice is to use silica sol or resin materials to perform high-temperature strengthening and low-temperature strengthening treatments. This method increases the complexity of the process. At the same time, it is not only not environmentally friendly, but also may cause adverse effects on the deformation of the core itself