Measures to prevent oxidation and slag inclusion in large aluminum castings
The casting should be designed to strictly control the smelting process, speed up the smelting speed, reduce oxidation, and completely remove slag inclusions. The aluminum-magnesium alloy should melt under the action of the covering. The stove and tools should be cleaned and preheated and dried after painting. The aluminum casting design pouring system must have a stable flow, buffer and slag removal capabilities. Inclined pouring system, stable liquid flow, no secondary oxidation; the selected coating of the casting has strong adhesion, does not peel off during pouring, and forms scum when entering the casting. Measures to prevent leakage and thermal cracks of the aluminum casting: avoid local overheating and reduce The stress of the gating system. The inclination angle of the mold core and the core must be greater than 2°. After the casting has solidified, the mold can be opened. If necessary, a sand core can be used instead of a metal core. Adjust the coating thickness to make the cooling rate of each casting uniform. Choose the appropriate casting temperature according to the casting thickness. Improve the alloy structure, improve the hot cracking performance; improve the casting structure, eliminate sharp corners and wall mutations, and reduce hot cracks.