Pouring temperature of metal zinc aluminum alloy castings
The pouring temperature is the temperature when the pouring liquid enters the pressure chamber, and the production temperature is controlled by the temperature of the alloy liquid in the holding furnace.
Control pouring temperature.
(1) zinc alloy
The upper limit of die casting temperature for complex parts is the upper and lower limit of thick wall parts and simple parts. Molten metal temperature and crucible enter gooseneck pot
The internal temperature is basically the same, and the die casting temperature is controlled by controlling the temperature of the metal liquid in the crucible. Excessive damage to books
1, combustion of aluminum and magnesium.
2, the rate of metal oxidation is accelerated, the amount of burning loss increases, and zinc slag increases.
3, thermal expansion will lead to the malfunction of the mold hammer.
4. Melt the iron in the iron crucible into alloy liquid and accelerate the reaction of aluminum and iron at high temperature.
The hard particles of intermetallic compounds cause excessive wear of Hammerheads and gooseneck tanks.
5, fuel consumption has increased correspondingly.
The temperature is too low: the fluidity of the alloy fluid is poor, which is not conducive to the forming and surface quality of the die castings.
(2) aluminum alloy
The casting shape and structure are different, pouring temperature is 310.
It can be controlled at 630~730 C; for thin walled complex parts, the flow of molten metal can be improved.
High temperature can be used to obtain good molding; for thick-walled structures, low temperature can be used to reduce solidification shrinkage.
When the injection temperature is too high, the absorption of aluminum in water will increase, which makes the thick wall of the parts easy to produce pinholes, shrinkage holes and surface bubbles, accelerates the corrosion of the mold, and causes premature cracking of the mold.
The pouring temperature is too low and the fluidity is poor, so it is easy to produce defects such as cold separation, flow pattern and insufficient casting.