Why are aluminum die casting defects prone to oxidation and slag formation

The oxidized slag is primarily distributed on the casting's upper surface, particularly at the corners of the casting mold, where no air is allowed to pass through. In most cases, the fracture is grayish-white or yellow in color, aluminum die casting parts and it is discovered through X-ray fluoroscopy or mechanical processing. It can also be discovered during alkaline washing, pickling, and anodizing processes.

 

 

The following are the causes:

1. The furnace charge is not clean, and the amount of back charge is excessive.

2. Inadequate design of the gating system
3. There is no cleaning of the slag in the alloy liquid.
4. An incorrect pouring operation results in the introduction of slag.
The lack of sufficient standing time following the refinement and deterioration treatments.
Method of prevention: 1. The amount of furnace charge that is used should be reduced in an appropriate manner.

2. Make improvements to the design of the gating system in order to improve its slag retention capability.

3. Make use of the appropriate flux to remove slag.

4. When pouring, die casting products is important to maintain stability and pay close attention to slag blocking.

5) After refining, the alloy liquid should be allowed to stand for a specified period of time before being poured into the mold.

The reason why aluminum die casting defects oxidize and slag is not well understood.

Preventive measures for aluminum alloy die casting defects caused by oxidation and slag inclusion include the following:

Control the smelting process of aluminum alloy castings to ensure that they are smelted quickly, that oxidation is reduced, and that slag is thoroughly removed. It is necessary to melt the Al-Mg alloy beneath the covering agent. Cleaning and removing oxides from the furnace and tools, as well as preheating the furnace and tools, are essential, and the paint should be thoroughly dried before use after coating. The pouring system that has been designed must have stable flow, buffering, and slag skimming capabilities, die casting aluminum among other things. The liquid flow is stable, and there is no secondary oxidation as a result of the use of the inclined pouring system. The paint chosen should have excellent adhesion and should not peel off during the pouring process, allowing slag inclusions to form in the aluminum alloy castings during the casting process.

ADC11 or ADC12 die castings are commonly used in aluminum alloy die castings. According to its chemical composition, ADC11 is composed of the following elements:
The chemical composition of the ADC11 Slag inclusion form, as well as the mechanism of its formation
Die casting defects in aluminum alloys, including oxidation and slag inclusion, are caused by the following factors:

The charge does not appear to be clean, and the amount of back charge is excessive.
Design flaws in the gating system
There is no cleaning of the slag in the alloy liquid.
Slag is brought in as a result of an incorrect pouring operation.
Inadequate standing time following refining and deterioration treatment