Hot chamber die casting is the method of die casting that involves a pressure chamber that is directly connected to the mold cavity. As an alternative to cold chamber die casting, this method is used to shape metals with low melting points like magnesium, zinc, lead and tin.
Related Categories
Since hot chamber casting requires a holding pot to be directly inside the casting furnace, a pump comes in direct contact with the molten metal. Therefore, metals with high melting points, like aluminum, brass, copper and lead-based alloys, would damage the pumping system and corrode the plunger because their temperatures are so high. They also may slightly melt the pot or plunger and may absorb some of the metals in which they are enclosed. For that reason, high melting point metals are cast only in cold chamber casters. Although the metals permitted in hot chamber die casting are limited, the process is quicker and offers a continuous flow as opposed to ladling, which requires manual labor and more time. Candy dispensing machines, parking meters and other similar products are often die cast in hot chambers. Hot chamber die casting tends to produce smaller items in higher volumes. Despite their inability to form metals with high melting points, hot chamber die casters are still very valuable metal casting tools.
While cold chambers are horizontal, hot chamber die casting machines are vertical feeding systems. They are sometimes informally called "gooseneck machines," which references their long, thin feeding tubes. Because they are vertically positioned, less hydraulic pressure is needed to feed the molten metal through the system. The metal is heated in a holding pot located inside the furnace. Hot chamber machines are smaller than cold chamber machines because they do not require a separate area for the holding pot. Once heated beyond its melting point, the metal flows from the pot to the shot chamber though an inlet by a plunger, which comes in direct contact with the metal. It is then injected into a mold under pressure, which usually operates at pressures between 1,000 and 10,000 PSI. The casting solidifies, and the part is ejected from the mold by a clamping unit release. These systems are usually hydraulically or pneumatically powered depending on their size.
