As aluminum alloy and other aluminum alloy die-casting products expand from time to time in the market, domestic aluminum alloy and other aluminum alloy die-casting products have developed rapidly in recent years. In the current good market conditions, whether it can be restricted by certain factors is also a concern of many people in the industry. Die-cast aluminum alloy is also a kind of die-casting. The knowledge introduced below is also about die-casting. So which ones are introduced in detail?
1. The control of alloy composition starts with the purchase of alloy ingots. The alloy ingots must be based on ultra-high-purity aluminum, plus alloy ingots made of ultra-high-purity aluminum, magnesium, and copper. The supplier has strict composition specifications. High-quality aluminum alloy material is the guarantee for the consumption of high-quality castings.
2. After purchasing alloy ingots, ensure that there is a clean and dry stacking area to prevent long-term exposure to moisture and white rust, or contamination by factory dirt, which increases the generation of slag and also increases metal loss. A clean factory environment is very effective for effective control of alloy composition.
3. The ratio of new material to the return material such as the nozzle, the return material should not exceed 50%, ordinary new material: old material = 70:30. The aluminum and magnesium in the continuous remelted alloy are gradually reduced.
4. When the nozzle material is remelted, the remelting temperature must be strictly controlled not to exceed 430°C to prevent the loss of aluminum and magnesium.
5. Die-casting plants with conditions are best to use a centralized furnace to condense aluminum alloys, so that the alloy ingots and the recycle materials are evenly proportioned, and the flux can be used more effectively, so that the alloy composition and temperature remain uniform and stable. Electroplating waste and fines should be melted separately.
In many cases, high-quality aluminum alloy die castings can be made without paying attention to the above problems. If the aluminum alloy die castings show the following defects, the following provides some treatment methods.
Since the causes of each type of defect come from a number of different influencing factors, it is necessary to deal with the problem in practical consumption. In the face of many reasons, is it the first to adjust the machine? Or to change the material first? Or to modify the mold? The proposal is difficult. Easy to level, first simplify and then deal with the complexity, the sequence:
1) Clear the parting surface, clear the cavity, clear the ejector; improve the coating, improve the spraying process; increase the clamping force and increase the amount of metal poured. These measures can be implemented with simple operations.
2) Adjust process parameters, injection force, injection speed, filling time, mold opening time, pouring temperature, mold temperature, etc.
3) Refueling, selecting high-quality aluminum alloy ingots, changing the ratio of new materials to recycled materials, and improving the smelting process. 4) Modify the mold, modify the gating system, add internal gates, add overflow grooves, exhaust grooves, etc.
For example, the reasons for flashing of die castings are:
1) Die casting machine problem: The clamping force is adjusted incorrectly.
2) Process problem: The injection speed is too high, which constitutes a pressure shock peak that is too high.
3) Mold problems: deformation, debris on the parting surface, uneven wear of inserts and sliders, and insufficient template strength.
