Wuxi Dongao Nonferrous Casting Co., Ltd.
Home > News > Content
Overcome Defects When Pouring Copper-aluminum Castings In Lost Foam Casting Process
- May 31, 2018 -

In the process of depositing copper-aluminum castings using lost foam casting, the problem of sand inclusion in the copper-aluminum castings is caused by the fact that the sand is rapidly mixed with the solution flowing into the cavity and mixed with the solution. If it is difficult to discover at the beginning, copper-aluminum castings will have a grit distribution on the surface after machining.


The sand trap of copper-aluminum castings has also become a white defect, and its existence will cause the castings to be scrapped. The actual production is very harmful. Therefore, it should be strictly avoided in production. In copper-aluminum castings, the location of sand inclusions is basically the same, one is the connection between the gate and the sprue; the other is the lower part of the connection between the sprue and the runner.


The joint between the sprue and sprue of the copper-aluminum casting is mainly due to the direct erosion of the sprue and the destruction of the coating by the molten metal, which will cause the sand to collapse. The lower part of the connection between the sprue and the runner is due to the high height of the sprue. When pouring, the drop of the molten metal is great, and the coating of the runner is destroyed, causing the sand to break into the cavity.


In order to solve this problem, the destruction of the coating should be prevented first. Since the degree of vacuum is high here, the coating thickness and strength can be increased to enhance the flow of the barrier sand irrespective of the air permeability of the coating at that location. The second is to combine the model and the gating system before packing.


In the case of lost foam casting copper-aluminum castings, it is necessary to seal the contact with the gating system when it is boxed, but the paint must be blown dry to prevent the wet paint from falling off. In addition, the pouring is to avoid the pouring of molten iron on the sprue, and the molten iron should flow through the gate cup to buffer and flow into the sprue.