A kind of cristobalite lost foam casting coating and its preparation method

Abstract

The invention discloses a cristobalite lost foam casting coating which is formed by processing cristobalite, graphite, bentonite, an organic binding agent and an additive. The preparation method of the cristobalite lost foam casting coating is characterized by comprising the following steps of: weighing 10-90 parts by weight of cristobalite, 5-90 parts by weight of graphite, 1.5-3.0 parts by weight of bentonite, 2.0-4.0 parts by weight of organic binding agent and 1.0-2.0 parts by weight of additives; adding water, mixing and stirring to form a paste with a baume degree of 22 Be'-33Be', thus obtaining the cristobalite lost foam casting coating. The cristobalite lost foam casting coating disclosed by the invention has the following advantages: the air permeability is good; the suspension is good; the volume expansion change after the coating is cast is small; the smooth coating on the surface of a casting can be automatically uncoated; the cost is saved; the process is simple; the yield of the casting is improved; the cristobalite lost foam casting coating can be extensively applied in the casting processing of metals.

Description

technical field [0001] The invention relates to a coating used in a cristobalite lost foam casting process, in particular to a cristobalite lost foam casting coating in the field of metal casting and a preparation method thereof. Background technique [0002] The lost foam casting process is generally to make a model with foam plastic or other organic matter first, and then coat the refractory paint on the organic matter model; bury the mold coated with refractory paint into the sand box, and then vacuumize to form a certain negative pressure to melt the molten The molten metal is poured into the mold, the organic model disappears, the molten metal is filled and cooled to obtain the product—casting. Lost foam casting technology is a new casting technology, it can be rapidly prototyping, and it is a new casting process that is widely promoted in the foundry industry. One of the core technologies of lost foam casting technology is the coating for lost foam casting. The perfor...

AI Technical Summary

Problems solved by technology

[0011] Corundum and British powder are used as refractory aggregates. Although the product is stable, the cost is high and the product is expensive. Therefore, an environmentally friendly, efficient and stable lost foam casting coating is urgently needed in the market.