Zinc alloy
Die Casting is a better die casting method. Zinc alloy die casting and aluminum alloy die casting have become two of the most mature die casting techniques in die casting technology. In the development of zinc alloy die casting, the use of zinc alloy die-casting techniques will make die-casting castings more perfect. Here are two techniques for zinc alloy die casting:
Zinc alloy is an alloy composed of other elements added on the basis of zinc. Often added alloy elements are aluminum, copper, magnesium, cadmium, lead, titanium and so on. Zinc alloys have a low melting point, good fluidity, easy fusion welding, brazing and plastic processing, corrosion resistance in the atmosphere, and easy recovery and remelting of residuals; however, they have low creep strength and are prone to natural ageing and cause dimensional changes. Melting method, die casting or pressure processing into the material. According to the manufacturing process can be divided into cast zinc alloy and deformed zinc alloy. Zinc Alloy Die Casting
The main additive elements of zinc alloys are aluminum, copper and magnesium. The zinc alloys can be divided into two types of deformation and casting zinc alloys according to the processing technology. Cast zinc alloys have good fluidity and corrosion resistance and are suitable for die-casting instruments and automotive parts. Wait.
Zinc Alloy Die Casting - Controlling Blowhole Generation:
The key is to reduce the amount of gas mixed into the casting. The ideal metal flow should be accelerated from the nozzle through the splitter cone and runner into the cavity to form a smooth and consistent metal flow. The use of conical flow channel design, namely pouring The flow should be gradually reduced from the nozzle to the inward gate to achieve this goal. In the filling system, the mixed gas is formed by mixing the turbulent flow with the metal liquid phase to form pores. From the study of the simulated die-casting process in which the molten metal enters the cavity from the casting system, it is obvious that the sharp transitional points and the incremental pouring in the runner are evident. The cross-sectional area will cause turbulence and gas flow in the metal liquid flow. The smooth metal liquid will help the gas to enter the overflow trough and exhaust trough from the runner and cavity and exit the die.
Zinc Alloy Die Casting - Causes of Shrinkage:
1. In the solidification process of the molten metal, shrinkage occurs due to the shrinkage of the volume or the lack of liquid metal in the final solidified part.
2. Partial overheating of castings or castings with uneven thickness results in slow solidification of a certain part, and formation of recesses on the surface when the volume shrinks. Due to the existence of pores and shrinkage holes, the holes may enter water when the die castings are subjected to surface treatment. When baking is performed after painting and electroplating, the gas in the pores expands by heat; or the water in the pores may become vapor and expand in volume. As a result, the casting surface blisters.
The most important thing in zinc alloy die casting is the control of the pores. To make the zinc alloy casting look glossy, it is necessary to have a certain understanding of the control of the pores, so that no zinc alloy castings with multiple surface pores will be produced in the casting work. Now.
