A kind of spinel-magnesium-based ceramic core and preparation method thereof

Abstract

A spinel-magnesium-based ceramic core and a preparation method thereof belong to the field of preparation of ceramic cores in the field of precision casting. The raw material of the spinel-magnesium-based ceramic core includes powder raw material and binder, the powder raw material is composed of the following components, and the mass percentage of each component is: spinel powder is 50% to 90%, zirconia powder is 0%-30%, titanium dioxide powder is 0%-5%, and the balance is magnesium oxide powder; the mass percentage of the binder in the mass percentage of the powder raw material is 15%-25%. The preparation method of the spinel-magnesium-based ceramic core is as follows: mix the powder according to the ratio, configure the binder, mix the preheated mixed powder and the binder to prepare a slurry, and use the hot pressure injection molding method for the slurry Molded and sintered. The spinel-magnesium-based ceramic core has the advantages of high strength, small shrinkage, easy removal, and improved thermal shock resistance.

Description

A spinel-magnesium-based ceramic core and preparation method thereof technical field The invention belongs to the ceramic core preparation technology technical field of precision casting field, relate in particular to a kind of spinel- Magnesium-based ceramic core and preparation method thereof. Background technique [0002] Today, ceramic cores are a critical part of forming the complex interior cavities of near-net shape investment casting castings. with the help of The ceramic core can obtain precision castings with a specific inner cavity shape, and together with the mold shell ensure the dimensional accuracy of the wall thickness of the precision castings. After the casting is complete, the ceramic core is removed from the casting by mechanical or chemical erosion. Ceramic cores are used in investment casting an irreplaceable role. Now, the ceramic cores for precision casting have silicon-based, aluminum-based and magnesium-based, etc., now mostly silicon-base...

AI Technical Summary

Problems solved by technology

[0003] At present, ceramic cores for precision casting include silicon-based, aluminum-based and magnesium-based, etc., and most of them are silicon-based, but the melting point of silicon-based ceramic cores is relatively low. The active elements react, and the phase change during preparation and use affects its dimensional stability

Although the aluminum-based ceramic core has a high service temperature, its core removal process is complicated (high pressure, strong acid or strong alkali conditions), pollutes the environment and corrodes alloy materials

Magnesium-based ceramic cores have the advantages of high bending strength and easy solubility in weak acids, but there are problems of high sintering shrinkage and poor thermal shock resistance

[0004] However, the existing disclosed ceramic cores doped with magnesia have metal oxide as the main crystal phase, adding magnesia whiskers to improve the compressive strength and impact strength of the product, and reduce the sintering temperature; Alumina is added to the magnesia ceramic core as a mineralizer to increase the operating temperature, or titanium dioxide is added as a mineralizer to promote the sintering of the core. However, the above technology does not solve the problem of high sintering shrinkage and thermal shock resistance. sex problem