Ten common problems in die casting production


Die casting is the most commonly used casting technology in the casting industry. There are various problems in die casting. These are the ten common problems in die casting:

1.Hammerhead Stuck

In order to avoid the hammer head stuck, you can start from two aspects: 1. In production, the temperature is often measured to avoid the hammer head and cylinder temperature is too high to cause the hammer head stuck; 2. The use of materials should choose high-quality alloy materials to avoid the infiltration of impurities. When putting back materials, attention should also be paid to not letting impurities mix, so as to avoid impurities sticking to the hammer head and causing the hammer head to be stuck.

2.Shot head stuck in Gooseneck

If the hammer is stuck, first wait until the equipment is at room temperature and try to rotate the hammer. If it does not move, then change the cylinder to solve the problem, take out the hammer. If you want to quickly solve the problem of stuck, the fastest way is the refueling pot.

3.When the die casting machine hits the material, there are often dozens of molds, and the material can not be hit. It is often necessary to wait a few minutes before hitting the material.

In this case, the nozzle head or body should be blocked. At this time, observe whether there is no bright spot at the top of the feed head. If all the sections are gray, it indicates that the nozzle is blocked. The solution is as follows:

1. Adjust the nozzle temperature;

2. Lower the time of hitting the nozzle by 0.1 to 0.2 seconds;

3. The cooling water of fixed mold is slightly turned down.

4.Die casting thin-wall products are easy to crack

It can be analyzed from the following points:

1. There may be problems with materials. When using die-casting materials, try to control the proportion of waste materials not to exceed 30%;

2, mold opening is not good, one is the top output imbalance; Second, the unreasonable opening of cooling water leads to the unbalanced temperature of the mold, and the filling flow alone is unreasonable.

3. Improper selection of process parameters, mainly in the retention time and ejection delay time errors, mold retention time should not be long, about 3s per mm wall thickness; The ejection delay cannot be long, generally 0.5-2s.

5.ADC14 material die casting process feedback material is hard, easy to wear tool situation

To solve this problem, you can see from the following points: 1, the most key is to come to oh composition does not allow impurities, that is to say, hard point, it is best to all should be new raw material ratio, can not use recycled materials, especially the quality of S1 element is better; 2. Gemstone blades specially produced for these hard alloys should be used, with a general service life of about 7 days.

6.Wondering why some aluminum die castings have black spots when polished?

There are several reasons: silicon oxide or aluminum oxide ingots may solve the problem. But most likely from the release agent, spray too much release agent or release agent of organic content is too high. At the temperature of hot aluminum, some of these organic compounds are reduced to carbon, and some become organic macromolecular polymers. Carbon molecules are mixed WITH polymers, and when aluminum castings are FORMED, THEY ARE CONTAINED on the surface and become the dark spots we see. So reduce the concentration of spraying agent, use other spraying agent; Or prolong the blowing time after spraying.

7.in the process of die casting, sometimes there is metal spatter.

Why do metal spatter sometimes appear? There may be several reasons for the original black spot: the mold closing between moving and fixed molds is not tight, and the gap between the two is large; Or the clamping force is not enough to cause metal splashing; Or die casting maneuvering, fixed die installation is not parallel; Or the span of the strut is large, and the ejection force causes the deformation of the sleeve plate and produces the spray. Encounter the above reasons can be solved by the following debugging: reinstall the mold; Increase the clamping force: adjust the die casting machine so that the moving and fixed die mounting plates are parallel to each other; A support plate is added to the moving die to increase the stiffness of the sleeve plate.

8.Why can’t the in-hole processing of aluminum die-casting exceed 0.25mm?

In order to be suitable for die casting, a lot of silicon is added to the aluminum alloy used in die casting. When the aluminum alloy condenses inside the die, this silicon rises to the surface, forming a silicon film that is very hard and very resistant. Some OEM designers take advantage of this property by designing the inner surface of the hole of the die cast directly as the bearing surface. This silicon surface layer is usually only 0.2 to 0.9mm thick. Processing too much, the bearing surface life will be shortened.

9.What are the reasons for the pattern after anodization of die castings?

At present, the main spraying and injection oil are not evenly distributed and converged in the local area, which leads to abnormal composition of the surface aluminum alloy or cold spots, so there is the phenomenon of the oxidized pattern; The pattern of oxidation and die casting on the grain is basically the same. 2, because the high-speed switching position is not appropriate, resulting in undercasting, oxidation will have patterns. 3. The textbook says that the content of copper ions in the oxidation tank is too high, which also produces patterns, but this situation is very rare.

10.Die casting mold adhesive

How to do when the die casting mold is sticky? First check whether the mold temperature is normal, suitable to reduce the alloy liquid pouring temperature and mold temperature; 2. Check whether the ratio of release agent is abnormal, try to change the release agent, debug the surface of spraying position for polishing, and carefully polish the nitride mold that has been nitride, to prevent the destruction of the surface of the nitride layer, the formation of more and more sticky situation; 4. Improve the design structure of pouring system to avoid continuous scouring of cavity wall or core by alloy liquid; 5. Modify the mold cooling system; 6. Adjust the process parameters of die casting, properly reduce the injection speed, and shorten the two-speed stroke.