High-compressive-strength composite modified sodium silicate sand for pump valve castings, and preparation method thereof

Abstract

The invention discloses high-compressive-strength composite modified sodium silicate sand for pump valve castings. A modified sodium silicate binder in the sodium silicate sand is higher in constant-temperature wet strength, thixotropy and rheological property compared with a conventional modified sodium silicate binder, high in reaction binding activity, green and environment-friendly, and lower in dosage; sand materials in a formula can be mixed to form a high-strength and high-breathability material, the added perfluoropolyether is high in lubricating property and high-temperature stability, and capable of effectively improving stress defects in the material, increasing compressive strength, and enabling the material to be more compact in structure, and bentonite-supported nano-calcium fluoride has lubrication and reinforcement effects in case of being dispersed in the sand materials, and capable of forming a non-stick impermeable layer and preventing sand sticking of the castings; and the composite modified sodium silicate sand is excellent in comprehensive performance, not liable to absorb moisture, high in use efficiency, fast to scatter and clean, and capable of meeting the pouring requirements of the high-accuracy pump valve castings.

Description

technical field [0001] The invention relates to the technical field of water glass sand, in particular to a composite modified water glass sand with high compressive strength for pump and valve castings and a preparation method thereof. Background technique [0002] Molding sand is mainly a kind of material used for molding in casting, which is made by mixing sand materials, adhesives and auxiliary substances according to different proportions. According to the different adhesives used, it can be divided into clay sand and water glass sand. , resin sand, etc. Among them, water glass sand has the advantages of high strength, low cost, simple process, and low pollution, and is widely used. [0003] Castings of pumps and valves have the characteristics of thin walls and complex shapes. In the casting process, the quality requirements for molding sand are particularly strict. The quality of molding sand is also an important factor related to the quality of castings. Although wat...

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Problems solved by technology

[0003] Castings of pumps and valves have the characteristics of thin walls and complex shapes. In the casting process, the quality requirements for molding sand are particularly strict. The quality of molding sand is also an important factor related to the quality of castings. Although water glass molding sand has significant advantages, there are also many Disadvantages, obvious defects are mainly manifested in low strength at room temperature, poor collapsibility, and difficulty in regenerating old sand. If it is not modified, it is difficult to improve the quality of pump valve castings