Novel acetylene carbon black coating process for sand casting

Abstract

The invention discloses a novel acetylene carbon black coating process for sand casting. The novel acetylene carbon black coating process for sand casting mainly comprises the following steps of 1) placing high-purity acetylene in a spray gun; 2) opening an acetylene gas switch to ignite acetylene gas at a nozzle; 3) adjusting the acetylene gas switch until the acetylene is in an incomplete combustion flame color state; 4) uniformly spraying the tail end of acetylene flame on a casting surface; and 5) after confirming that coating is completed, closing the spray gun, and completing coating. According to the novel acetylene carbon black coating process for sand casting, through acetylene carbon black coating, the coating is compact in appearance and good in coating property, has good leveling property, can prevent liquid metal from being immersed in a casting gap, and can prevent the coating from forming indents, and a casting with a smooth surface can be obtained.

Description

technical field [0001] The invention belongs to the technical field of sand casting, in particular to a novel acetylene carbon black coating process for sand casting. Background technique [0002] In aluminum alloy dry sand casting, casting coatings are generally evenly coated on the surface of the sand mold and sand core. Sand and other properties, after coating, it can reduce the defects of castings such as sand sticking, insufficient pouring, and sand holes. [0003] Different working conditions have different quality requirements for coatings. For ordinary aluminum alloy sand casting, after the surface of the sand mold is coated with casting paint, the fluidity of the liquid metal in the cavity is better, so the casting will not form defects such as insufficient pouring and blisters. In the sand casting of large and complex thin-walled aluminum alloy castings, since the liquid metal receives much greater resistance than ordinary sand casting in the flow direction, and ...

AI Technical Summary

Problems solved by technology

In the sand casting of large and complex thin-walled aluminum alloy castings, since the liquid metal receives much greater resistance than ordinary sand casting in the flow direction, and the larger and thinner the casting, the greater the filling resistance. If the quality of the coating is not good Well, the thin-walled part of the casting cannot be fully filled by the molten metal at the end, and there will be serious problems of insufficient pouring and sand sticking. This kind of insufficient pouring will cause the casting to be scrapped, and it is also difficult to clean the sticky sand, and the surface quality of the casting is also poor.

[0004] At present, in the casting coating system, there is no special coating suitable for sand casting of large and complex thin-walled aluminum alloy castings. Generally, casting coatings are selected from aggregate, suspension Composed of agent, carrier liquid, binder and additives, the penetration depth of the coating and the uniformity of the coating cannot well meet the process requirements of sand casting of large and complex aluminum alloy castings.

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