As aluminum alloy and other aluminum alloy die-casting products continue to expand in the market, domestic aluminum alloy and other aluminum alloy die-casting china products have developed rapidly in recent years. In the current good market conditions, whether it will 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 what are the specific introductions?
- 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 standards. High-quality aluminum alloy material is the guarantee for the production of high-quality castings.
- 2. After purchasing alloy ingots, ensure that there is a clean and dry stacking area to avoid long-term exposure to moisture and white rust, or contamination by factory dirt and increase slag production and increase 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%, general new material: old material = 70:30. The aluminum and magnesium in the continuous remelted alloy gradually decrease.
- 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. Die-casting plants with conditions are best to use a centralized melting furnace to melt aluminum alloys, so that the alloy ingots and the re-fired materials are evenly proportioned, the flux can be used more effectively, and the alloy composition and temperature are kept 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 have the following defects, the following provides some solutions.
Since the causes of each type of defect come from many different influencing factors, it is necessary to solve the problem in actual production. In the face of many reasons, is it the first to adjust the machine? Or change the material first? Or modify the mold first? The degree of ease, simplify first and then complex to deal with, the order:
- 1) Clean the parting surface, clean the cavity, clean the ejector rod; 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) Change materials, choose high-quality aluminum alloy ingots, change the ratio of new materials to reworked materials, and improve 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, resulting in 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.