Sintering resisting type burnt-on sand coating and preparation method thereof

Abstract

The invention relates to the field of casting technical materials, and particularly relates to a sintering resisting type burnt-on sand coating and a preparation method thereof. The coating comprisesa refractory aggregate, a carrier, a suspending agent and an adhering agent, wherein the refractory aggregate comprises the following materials in parts by mass: 30-50 parts of kieselguhr, 30-50 partsof asbestos powder, 5-15 parts of talcum powder, 5-15 parts of mica powder, 5-15 parts of aluminum silicate, and 5-10 parts of kaolin; the mass of the carrier is 100-150% of the mass of the refractory aggregate; the mass of the suspending agent is 3-10% of the mass of the refractory aggregate; and the mass of the adhering agent is 5-15% of the mass of the refractory aggregate. The coating is highin high temperature strength and stability, and low in gas evolution; when coating a sand core with the coating, the refractory material in the coating is capable of insulating heat, so that the heating time of the sand core can be delayed, and the sand core is prevented from overheating sintering, and as a result, a casting product quality is obviously improved; the sintering preventing effect is obvious; and the problem of sintering burnt-on sand produced by pouring a jacket core of an engine cylinder body, a water channel core and air channel core of a cylinder cover, or a small core, a thin hole, a narrow hole and a blind of a hydraulic valve part, and the like can be effectively solved.

Description

Technical field [0001] The invention relates to the field of casting process materials, in particular to an anti-sintering sand-stick coating and a preparation method thereof. Background technique [0002] In the production of complex castings such as engine blocks and heads, due to the increasing requirements of engines, increasing power, lighter weight, and emission requirements. This requires the wall thickness of the cylinder block and head to be thinner and thinner, and the structure is more complicated. This puts forward very strict requirements for casting production. For example, sand cores are required to be more complex, thinner and smaller, and pouring temperature is required higher, but at the same time, the requirements for the cleanliness of the inner cavity of the casting are higher (inner cavity residue ≤ 3 grams). [0003] The main problem in pouring this type of casting is the sticky sand of the casting. The formation of sticky sand is divided into two stages. ...

AI Technical Summary

Problems solved by technology

[0005] In the prior art, there are two main methods to solve the problem of metal permeable mechanical sand sticking: 1) reduce the particle size of the sand core, because the castings such as the cylinder block and the head are complicated, the exhaust of the sand core is not smooth, and the sand core develops at high temperature. The air volume can only pass through the gap between the sand grains and be discharged out of the mold through the core head. If the grain size of the sand core is adjusted finer, the pores will increase significantly; 2) Increase the content of silica. If refined quartz sand is used, the silicon content can reach more than 98%. , but the deformation of quartz is serious, and it is easy to form shackles due to the cracking of the quartz sand core at high temperature