Coating for metal mold casting of magnesium alloy thin-wall parts

Abstract

The invention discloses a coating for a metal mold casting of magnesium alloy thin-wall parts, wherein the coating consists of following components, by weight percent, 1.5 to 2.5% of diatomaceous earth, 2 to 3% of magnesia powder, 1.2 to 1.8% of titanium dioxide powder, 1 to 2% of zircon powder, 1.5 to 2.5% of bentonite, 2 to 4% of asbestos powder, 1.2 to 1.4% of silica sol and the balance of alcohol.

Description

technical field [0001] The invention relates to the field of casting, in particular to a coating for metal mold casting of magnesium alloy thin-walled parts. Background technique [0002] Metal mold casting, also known as hard mold casting, is a casting method in which liquid metal is poured into metal molds to obtain castings. Cast molds are made of metal and can be used repeatedly (hundreds to thousands of times). The castings that metal mold casting can produce at present have certain restrictions in terms of weight and shape. For example, the weight of castings should not be too large; the wall thickness is also limited, and it is difficult to cast smaller castings with wall thickness. [0003] Due to the fast cooling rate of magnesium alloy thin-walled parts in the metal mold casting process, it is easy to form defects such as cold shut, pinholes and shrinkage porosity in the castings, so that the castings are scrapped. Therefore, how to improve the quality of magnesiu...