Sand-burning-resistant water-based expendable pattern coating for gray iron casting and application and preparation method thereof

Abstract

The invention relates to the technical field of expendable pattern casting, and specifically, to a sand-burning-resistant water-based expendable pattern coating for gray iron casting and application and a preparation method of the coating. According to the coating, flaky graphite, mullite, and light calcined magnesia are organically matched, so that the coating is difficult to penetrate through bycontinuous high-temperature molten iron. By optimizing resin and an auxiliary, the coating is high in drying speed under an oven-drying condition of 70 to 85 DEG C, and can also be smoothly operatedin a severe environment; and by utilizing the light calcined magnesia and the flaky graphite, the coating can be easily peeled off from the surface of a cast piece after being poured, the cast piece is good in appearance quality, the later fire treatment is not needed, and the casting time is greatly saved. White rubber powder, styrene-acrylate resin, and two inorganic adhesives are utilized, so that the hardness of the coating is improved, a model is difficult to damage, and the coating is difficult to permeate under the scouring of the molten iron. By utilizing a JFC penetrating agent and asurfactant, the adhesiveness of the coating and EPS foam is good, the bareness is difficult in a brushing process, an air hole can be guaranteed in the surface of the dried coating, and the air permeability of the coating is guaranteed.

Description

technical field [0001] The invention relates to the technical field of lost foam casting, in particular to an anti-sand sticking water-based lost foam coating for gray iron casting, an application and a preparation method of the coating. Background technique [0002] Lost foam casting technology, referred to as EPC. Belonging to solid casting, EPC castings have high shape and size and good repeatability, and are widely used in automotive molds, machine tool shells, cylinder shells and other fields. Modern machinery pursues precision and function, and the complexity and precision of parts and housings have increased significantly. Traditional casting is usually time-consuming and labor-intensive, so EPC is widely used. At present, most complex parts, casings, and precision parts are manufactured by EPC. In order to control the appearance quality and precision of complex parts, EPC often needs to use suitable separation coatings to separate molten iron and molding sand. Lost...

AI Technical Summary

Problems solved by technology

Lost foam coating is especially important for the quality of castings, especially for thick, complex and deep cavity parts. Due to high casting temperature and slow cooling, phenomena such as sticky sand, pores and impurities often occur, which may lead to long post-processing process time. , the dimensional accuracy of the workpiece is affected, the processing cost is high, etc., which will lead to the scrapping of the workpiece

[0003] It can be seen that the existing lost foam coatings still need to be improved, and their heat resistance has not yet reached the ideal level. Therefore, for the particularity of thick and large gray iron castings, the lost foam coatings should be specially designed

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