Mold coating and method for preparing the same

Abstract

The invention provides a mold coating. A mold is used for producing an aluminum alloy part. The mold coating is at least partially attached to the inner wall of a mold cavity. The materials of the coating comprise NaCl and / or KCl, NaF, CaF2, K3AlF6, Na2SO4 and / or K2SO4. When the mold is a metal mold, the materials of the coating further comprise graphite. When the mold is a plaster mold, the materials of the coating further comprise graphite and CaCO3, and the thickness of the coating can be selected to range from 0.5 mm to 5 mm. According to a preparation method of the mold coating, the materials of the coating are sprayed or dip-coated to the inner wall of the mold cavity after being subjected to hot melting.

Description

technical field [0001] The application relates to the field of casting technology, in particular to a mold coating and a preparation method thereof, which are suitable for aluminum alloy casting. Background technique [0002] In the field of casting, aluminum alloy castings are a kind of casting with large output and wide application due to their high strength and light weight. Generally speaking, various casting methods such as sand casting and metal casting in special casting, high pressure casting, Low pressure casting, investment casting, lost foam casting, etc. are all suitable for the manufacture of aluminum alloy parts. There are mainly three kinds of molds used in aluminum alloy casting, one is ordinary sand mold, one is plaster mold, and the other is permanent mold or metal mold. Different casting processes are suitable for molds of different materials, such as ordinary sand casting Investment casting, lost foam casting, etc. in special casting use sand molds, meta...

AI Technical Summary

Problems solved by technology

[0003] Different casting methods follow the general casting process. First, the aluminum alloy solution must be refined and impurity removed, and then the molten metal is poured into the mold through different pouring systems and injection methods. In the prior art, the impurity removal of aluminum alloy In addition to being carried out in melting furnaces, it can also be carried out in some special casting equipment such as holding furnaces or crucibles of low-pressure casting machines. Filters can also be placed at multiple positions in ladles, hoppers, and runners to repeatedly process the aluminum alloy liquid. Second degassing and impurity removal, some casting methods such as low-pressure casting, the aluminum alloy liquid is melted in the holding furnace or crucible in many cases and directly enters the mold cavity through the liquid riser, the degassing and impurity removal conditions are subject to many restrictions, even Ordinary casting methods or special casting methods with relatively flexible process operations are limited by actual casting conditions, or are related to the parts to be produced (such as large parts), and the purification of aluminum alloy liquid is also incomplete or not suitable for operation.