Pressure casting is abbreviated as die casting, which i […]
Pressure casting is abbreviated as die casting, which is a casting method that pours molten alloy liquid into the pressure chamber, fills the cavity of the steel mold at high speed, and solidifies the alloy liquid under pressure to form a casting. The main characteristics of die casting different from other casting methods are high pressure and high speed.
(1) The molten metal fills the cavity under pressure and crystallizes and solidifies at a higher pressure. The common pressure is 15-100 MPa.
(2) The molten metal fills the cavity at a high speed, usually in the range of 10-50 meters/second, and some may exceed 80 meters/second, (the linear velocity of the cavity introduced through the gate-the speed of the gate), so the metal The filling time of the liquid is extremely short, which can fill the cavity within about 0.01-0.2 seconds (depending on the size of the casting). The die-casting machine, die-casting alloy and die-casting mold are the three major elements of die-casting production, which are indispensable. The so-called die-casting process is the organic use of these three elements to enable stable and rhythmic and efficient production of qualified castings with good appearance, intrinsic quality, and dimensions that meet the requirements of drawings or agreements, or even high-quality castings.
Flowability of die casting
Flowability refers to the ability of the alloy liquid to fill the mold. The size of the fluidity determines whether the alloy can cast complex castings. The eutectic alloy has the best fluidity among aluminum alloys.
There are many factors that affect the fluidity, mainly the composition, temperature and solid phase particles of metal oxides, metal compounds and other contaminants in the alloy liquid, but the external fundamental factors are pouring temperature and pouring pressure (commonly known as pouring head) The height.
In actual production, in addition to strengthening the smelting process (refining and slag removal), it is also necessary to improve the moldability (sand mold breathability, metal mold exhaust and temperature) in addition to strengthening the smelting process (without affecting the alloy). Under the premise of casting quality, increase the pouring temperature to ensure the fluidity of the alloy.
Aluminum and aluminum alloys processed into a certain shape are collectively referred to as aluminum, including plates, strips, foils, pipes, rods, wires, and profiles.