Preparation method of sand core dip-coating coating and prepared coating

Abstract

The invention relates to a preparation method of a sand core dip-coating coating and the prepared coating. The preparation method comprises the following steps that ethyl acetate and water are uniformly mixed according to a ratio of 1: 3 to obtain a component A; uniform mixing is carried out according to the proportion of 5% of phenolic resin, 40% of zircon powder, 20% of graphite powder, 1% of iron oxide powder, 5% of bentonite, 3% of mica powder, 1% of a defoaming agent and 25% of water to obtain a component B; and the component A and the component B are mixed and stirred according to the ratio of 1: 1 to obtain the sand core dip-coating coating. The coating prepared by the preparation method has the advantages of small gas generation amount, high coating strength, high chilling capability for castings, rapid cooling and solidification of molten iron and improvement of casting quality, and therefore the problem of veining sand casting is effectively solved.

Description

Technical field [0001] The invention relates to the field of casting, in particular to a preparation method of sand core dip coating and the prepared coating. Background technique [0002] Cylinder block is the largest individual component in the engine. In the production of engine block casting, modeling and core making costs account for about half of the total cost of casting production, metal melting accounts for a quarter of the cost, and the remaining quarter The cost is spent on casting cleaning and post-treatment processes; among them, 70% of the cleaning process cost is closely related to the molding and sand core. [0003] The main domestic sand core processes include cold core box core making and hot core box processes; the sand core prepared by the ordinary cold core box method has the advantages of high strength, fast hardening, high dimensional accuracy of the sand core, and good collapsibility. However, there are problems such as veining of castings and the inability...

AI Technical Summary

Problems solved by technology

[0003] The main domestic sand core technology includes cold box core making and hot core box technology; the sand core prepared by the ordinary cold box method has the advantages of high strength, fast hardening, high dimensional accuracy of the sand core, and good collapsibility. However, there are problems such as casting veins, and the inner cavity of complex parts cannot be cleaned, especially the inner cavity of the water jacket and oil passage of the engine cylinder, which are often reworked and scrapped due to the veined casting sand.

[0004] The defects of cold-core veined casting sand are generally solved by special sand or coating technology; however, because the high price of special sand brings a large burden on the production cost of the enterprise, it is generally considered to use special sand; for coating, the current foundry industry There are many types of coatings in China, and there is a large gap in their functional effects, but no effective coatings have been found for the defects of veined casting sand.