Characteristics of oxidation slag inclusion defect of aluminum casting: oxidation slag inclusion is mostly distributed on the upper surface of the casting, at the corner where the mold is not ventilated. The fracture is mostly gray white or yellow, which can be found through X-ray fluoroscopy or during machining, as well as during alkali cleaning, acid cleaning or anodizing.
Cause:
The furnace charge is not clean, and the amount of recycled material is too much.
The gating system is poorly designed.
The slag in the alloy liquid is not removed completely.
Slag inclusion caused by improper pouring operation.
The standing time after refining and modification is not enough.
Prevention method:
The furnace charge shall be blown sand, and the usage of the returned material shall be reduced appropriately.
Improve the design of gating system to improve its slag retaining capacity.
Use appropriate flux to remove slag.
The pouring shall be stable and attention shall be paid to slag blocking.
The alloy liquid shall be kept for a certain time after refining and before pouring.
