Composite modified sodium silicate-bonded sand fast to solidify for pump valve castings and preparation method of composite modified sodium silicate-bonded sand

Abstract

The invention discloses composite modified sodium silicate-bonded sand fast to solidify for pump valve castings. Compared with a conventional modified sodium silicate adhesive, a modified sodium silicate adhesive in the sodium silicate-bonded sand is more excellent in normal-temperature wet strength, the thixotropy and rheological property are better, and the reaction binding activity is high; in addition, environmental friendliness is achieved, and a good binding effect can be achieved through a small quantity of the adhesive; network structures can be formed between sand materials through silica sol added in the sand materials, and the binding strength is improved while the hardening speed of the sodium silicate is increased ; nano calcium fluoride carried by bentonite is dispersed in the sand, the lubricating effect and the reinforcing effect are achieved, and a non-stick impermeable layer can be formed, so that infiltration and sand adhesion of molten metal are prevented. The composite modified sodium silicate-bonded sand is excellent in comprehensive performance, bright and clean in surface, good in moisture resistance, short in production period and fast to scatter and clean, and the production efficiency is substantially improved.

Description

technical field [0001] The invention relates to the technical field of water glass sand, in particular to a rapidly solidified composite modified water glass sand 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 water glass mol...

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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