Glass-powder-contained high-breathability water-base expendable pattern casting coating for magnesium alloy casting and preparing method for glass-powder-contained high-breathability water-base expendable pattern casting coating for magnesium alloy casting

Abstract

The invention discloses a glass-powder-contained high-breathability water-base expendable pattern casting coating for magnesium alloy casting. According to the expendable pattern casting coating, kieselguhr subject to heat conduction modification serves as refractory aggregates; and meanwhile, raw materials such as magnesium hydrate and glass powder are added so that a coating layer can be heated in the pouring process to form a compact and even protection layer, molten metal can be effectively prevented from overflowing, meanwhile, the temperature in a cavity can be adjusted, and magnesium alloy oxidation burning can be prevented. The interior of the prepared coating is of an even fiber network structure, the coating performance is good, the water content is low, and the beneficial effects of being breathable, capable of achieving heat conduction, low in coefficient of thermal expansion and the like are achieved; and after the coating is used, a casting with high surface smoothness and low porosity can be obtained, and the magnesium alloy casting quality is effectively improved.

Description

technical field [0001] The invention relates to the technical field of lost foam casting coatings, in particular to a high-permeability water-based lost foam coating containing glass powder for magnesium alloy casting and a preparation method thereof. Background technique [0002] In recent years, magnesium alloys are gradually replacing part of iron and steel due to their excellent comprehensive properties, and have become more and more widely used materials, especially in the fields of automobiles and aviation, and lost foam casting magnesium alloy castings are also eye-catching The use of lost foam casting technology has the advantages of simple process, high casting dimensional accuracy, and small machining allowance. However, due to the low pouring temperature in the lost foam casting process of magnesium alloy castings, it is difficult to gasify the lost foam, and Most of the molds are in liquid state, and the magnesium metal is active, so it is easy to oxidize and bur...

AI Technical Summary

Problems solved by technology

"Development of Magnesium Alloy Coatings for Lost Foam Casting with Quartz Powder" uses quartz powder and diatomite as refractory aggregates, sodium bentonite and CMC as suspending agents, and dextrin and silica sol as binders to prepare high-permeability coatings. Magnesium alloy lost foam coating with flame retardant effect, however, the thermal conductivity of the coating formed during the casting process of this coating is poor, resulting in high temperature in the cavity, unsatisfactory flame retardant effect, and a large amount of combustion and oxidation of magnesium metal leads to serious defects in castings