The Identification And Elimination Of Significant Flaws In Die Castings Made Of Aluminum Alloys

1. Flow marks and patterns that are displayed on aluminum alloy die castings.
The flow pattern of the metal liquid causes the surface of aluminum alloy die-casting parts to be striped in a direction that is consistent with the direction of flow. There are obviously lines that don't go anywhere that are a different color from the metal matrix and don't follow any kind of progression pattern. Either an excessive amount of paint was sprayed into the mold cavity, or the quality of the paint was subpar, which is the reason for the pattern.

2. The following are the reasons for this problem: there are cracks on the surface of the cavity of the die-casting mold the preheating of the die-casting mold was uneven.
Die-casting factories that work with aluminum alloys need to pay careful attention to the following key points:In order to remove tension from the cavity, molds for die-casting should be annealed either on a regular basis or after a predetermined number of castings. If cracks have appeared on the surface of the mold cavity, the molding surface should be polished to remove the crack layer. The aluminum alloy die-casting factory should preheat the die-casting mold evenly when preheating it. If cracks have appeared on the surface of the mold cavity, the molding surface should be polished.

3. The intersection edges are sometimes smooth, and when this occurs, they are more likely to crack when subjected to the action of an outside force.
Things that the factory that does aluminum alloy die-casting needs to pay attention to include the following: the two metal flows are connected to each other, but they are not completely fused and there is no inclusion between them, and the bonding force between the two metals is very weak; the pouring temperature or the temperature of the die-casting mold is low; the runner position is incorrect or the flow path is too long; the filling speed is low.



Reduced size Die castings made of aluminum alloys have a rough surface that is indented in the shape of disks in a smooth pattern. The reasons for this are as follows: improper design of aluminum alloy die-casting parts due to shrinkage and an excessively large wall thickness difference; improper runner position; low injection specific pressure and a short holding time aluminum alloy die-casting factory; and the local temperature of the die-casting mold is too high. The design of the cooling system is illogical; the mold is opened at an inappropriately early stage; the pouring temperature is excessive.

4. Aluminum alloy die-casting factories need to check the following areas.
The end face of the ejector pin is worn due to the ejection component; the adjustment length of the ejector pin is inconsistent; the splicing part of the die-casting mold cavity does not match well with other parts; the ejector pin adjustment length is inconsistent. The inserting parts are loose because of splicing or movable parts; the movable parts are loose or worn; the side wall surface of the aluminum alloy die-casting part is formed by the inserts of the moving and fixed molds interpenetrating each other. This is caused by the fact that the inserts of the moving and fixed molds are interpenetrating each other.

Adjusting the length of the ejector rod to the correct position and tightening the insert or any other movable parts are the solutions and prevention methods. Adjust the length of the ejector rod to the appropriate position. During the design phase, round off any sharp corners and make any necessary adjustments to the clearance;if you improve the structure of the aluminum alloy casting, you can get rid of the intersecting inlay form in the die-casting mold, which will also allow you to improve the structure of the die-casting mold.

5. The die-casting parts made of peeled aluminum alloy have some surfaces that are shiny, and other surfaces that are a dark gray color.
Clean the cavity pressure chamber and pouring system before die-casting, removing any metal or non-metallic adherents; clean the alloy after it has been poured; select appropriate coatings, and the coating should be uniform. These are the solutions and the methods for preventing the problem.

6. Fracture
When die castings made of aluminum alloy are immersed in an alkaline solution, the cracks that form will take on a dark gray color.

The mold retention time is too short, as is the pressure holding time; there is a significant change in the wall thickness of the aluminum alloy die-casting parts; the local tightening force is excessively high, and the force is not evenly distributed during ejection aluminum alloy casting; the mold retention time is too short. Solutions to problems and measures to avoid them:

1. Make sure you have the composition of the alloy under control.
2. Raise the temperature of the mold; alter the casting structure; fine-tune the mechanism for extracting the core; or ensure that the push rod is evenly stressed.
3. Raise the draft angle and apply a potent release agent in the immediate area.
4. Lengthen the amount of time the mold is retained and the amount of time it is held under pressure.