Problems to be noticed in the production of alloy zinc

Problems to be noticed in the production of alloy zinc

1. Control of alloy composition From the beginning of purchasing alloy, alloy zinc strip must be based on extra-high purity zinc, plus extra-high purity aluminum, magnesium, copper alloy zinc strip, the supplier has strict composition standards. High quality zinc alloy material is the guarantee of producing high quality castings.

2. The purchased alloy zinc plate should be ensured to have a clean and dry stacking area, so as to avoid the appearance of white rust when exposed to moisture for a long time, or the production of slag caused by the pollution of factory dirt, and the increase of metal loss. A clean factory environment is useful for the effective control of alloy composition.

3. New material and water outlet and other return charge ratio, return charge should not exceed 50%, general new material: old material = 70:30. Continuous remelting alloys of aluminum and magnesium gradually decrease.

4. When the nozzle material is remelting, the remelting temperature must be strictly controlled not to exceed 420℃ to avoid the loss of aluminum and magnesium.

5. Qualified die casting plant is best to use centralized furnace to melt zinc alloy, so that the alloy zinc plate and return charge uniform ratio, flux can be used more effectively, so that the alloy composition and temperature to maintain uniform and stable. Electroplating waste, fine chips should be separate furnace.

All kinds of decoration, such as furniture accessories, architectural decoration, bathroom accessories, lighting parts, toys, tie clips, belt buckles, all kinds of metal buckle are widely used in the alloy zinc foil, which requires the casting surface quality to be high, and need to have good surface treatment performance. The most common defect of alloy zinc foil is surface foaming. The main reason is stoma and contraction mechanism, stoma is usually round, and contraction is irregular. Control air hole, the key is to reduce the amount of gas in mixed with the casting, the ideal metal flow should be accelerated by the nozzle after cone and sprue into the mold, forming a smooth and metal flow in the same direction, the taper runner design, namely water flow should be accelerated to from the nozzle to the gate to reduce gradually, can achieve this goal. In the filling system, the gas mixed is due to the mixing of turbulence and liquid metal, and the pores are formed. From the study on the simulated die-casting process of liquid metal entering the cavity from the casting system, it is obvious that the sharp transition position in the sprue and the increasing sprue cross-sectional area will lead to the turbulent flow of liquid metal and the gas entrapment. Smooth metal liquid is conducive to gas from the sprue and cavity into the overflow and exhaust groove, discharge outside the mold.