Problems in production of aluminum alloy die castings

Problems needing attention in the production process of aluminum alloy die castings

With the continuous expansion of the application range of aluminum alloy die casting products in the market, domestic aluminum alloy die casting has developed rapidly in recent years. In the current market situation, whether it will be restricted by some factors, which is also the concern of many people in the industry. Die casting aluminum alloy, it is also a kind of die casting, the knowledge introduced below is also about die casting, so what is the specific introduction?

1. The control of alloy composition begins with the purchase of alloy ingots. On the basis of high purity aluminum and magnesium alloy, high purity aluminum ingot must be added. Suppliers have strict composition standards. High quality aluminum alloy is the guarantee of producing high quality castings.

2. The purchased alloy ingots should have a clean and dry stacking area, so as to avoid white rust caused by long-term dampness or pollution by factory dirt, increase slag production and increase metal loss. A clean factory environment is very useful for effective control of alloy composition.

3. The proportion of new material to intake and other recycled materials shall not exceed 50%. Generally, new material: old material = 70:30. The content of Al and Mg in the continuous remelting alloy decreases gradually.

4. When the nozzle material is remelted, the remelting temperature must be strictly controlled not to exceed 430 ℃ to avoid the loss of aluminum and magnesium.

5. If the conditions permit, the centralized melting furnace is used to smelt aluminum alloy, so that the proportion of alloy ingot and recycled material is uniform, the flux is used more effectively, and the alloy composition and temperature are kept uniform and stable. Electroplating waste and fines should be smelted separately.

In most cases, it is not necessary to pay attention to the above problems in order to produce high quality aluminum alloy die castings. If the following defects exist in aluminum alloy die castings, some treatment methods are provided below.

Because each kind of defect is caused by many different factors, this problem must be solved in actual production. In the face of many reasons, should we adjust the machine first, change the material first, or modify the mold first? It is suggested to deal with it according to the degree of difficulty

1) Cleaning parting surface, cavity and ejector pin; improving coating and spraying process; increasing clamping force and pouring metal amount. These measures can be achieved by simple operation.

2) Adjust process parameters, injection force, injection speed, filling time, mold opening time, pouring temperature, mold temperature, etc.

3) In order to change the raw materials, high-quality aluminum alloy ingots were selected, the ratio of new materials to recycled materials was changed, and the smelting process was improved.

4) Modify the mold, modify the gating system, add the inner gate, add the overflow groove, exhaust slot, etc.

For example, the causes of flash in die castings are as follows:

1) Die casting machine problem: locking force adjustment is not correct.

2) Process problems: the injection speed is too high and the pressure impact peak value is too high.

3) Die problems: deformation, debris on parting surface, uneven wear of insert and slider, insufficient strength of template.