High-temperature-resistant coated sand and preparation method thereof

Abstract

The invention relates to high-temperature-resistant coated sand and a preparation method thereof. The high-temperature-resistant coated sand is prepared from 70-100 parts of silicon sand, 20-40 partsof modified phenolic resin, 5-15 parts of calcium stearate, 10-20 parts of silane coupling agents, 8-68 parts of high-temperature-resistant additives, 3-8 parts of microcrystalline wax and 10-20 partsof lubricants. The preparation method comprises the following steps that the silicon sand, the modified phenolic resin, the calcium stearate and the silane coupling agents are mixed to obtain a mixture A; the high-temperature-resistant additives and the microcrystalline wax are mixed to obtain a mixture B; the mixture B is added into the mixture A, meanwhile the lubricants are added, sufficient mixing is conducted, and then a mixture is placed into a heating machine to be heated for 20-40 min; then the mixture is continuously stirred and cooled till the room temperature is reached, and then amixture C is obtained; and the mixture C is screened and then calcinated, the calcinating temperature is 300-400 DEG C, the calcinating time is 60-80 min, and then crushing is conducted to obtain thehigh-temperature-resistant coated sand. Compared with ordinary coated sand, the high-temperature-resistant coated sand has the characteristics that the anti-bending strength is high, heat resistanceis good, and the hardness is large, the finished product rate of castings can be increased, and meanwhile the sand is not prone to being pasted in the castings.

Description

technical field [0001] The invention relates to the technical field of preparation of coated sand, in particular to a high-temperature resistant coated sand and a preparation method thereof. Background technique [0002] Coated sand refers to the molding sand or core sand whose surface is covered with a layer of solid resin film before molding. Due to the advantages of high strength, low gas generation, high dimensional accuracy of production castings, smooth surface and easy storage, coated sand has been widely used in recent years. However, the current coated sand has disadvantages such as low high temperature resistance, poor fluidity, and short high temperature heat resistance time, which cannot meet the needs of existing production. In order to solve the above problems, those skilled in the art have conducted research on high-temperature-resistant coated sand and its preparation method, wherein the patent with publication number CN104588569A provides a fast-curing high...

AI Technical Summary

Problems solved by technology

However, in practical applications, the high temperature resistant coated sand has relatively poor bending strength and low hardness at room temperature.