Permanent Mold Casting

Permanent mold casting is a method of producing metal parts with molten metal under the pressure of gravity or a pressure feed system poured into a static mold. This method is very common for non-ferrous metals, such as aluminum, copper, and magnesium alloys. The advantages of permanent mold casting are that it can achieve higher dimensional and surface quality tolerance comparable to sand casting without secondary work, and that it has a lower cost per part for large run production. The main disadvantage of permanent mold casting is that the molds have high initial cost. While called permanent, molds can wear or fail over time due to thermal stress.

Die Casting

Die casting is a method of producing metal parts by forcing molten metal into a mold or die under high pressure. This method is limited to low melting temperature metals, such as magnesium, aluminum, and zinc alloys. The advantages of die casting are that it can achieve complex feature geometry, hole tolerance comparable to drilling and boring machining process, and minimal secondary work to achieve desired surface tolerances. The main disadvantage of die casting is that the part geometry is limited in maximum thickness to allow the molten metal to fill the cavity without defects or voids.

There are two major types of die casting: hot chamber and cold chamber. The difference between them is the temperature and pressure involved in the process. In hot chamber die casting, the molten metal is kept in a furnace attached to the machine, and a plunger pushes the metal into the die cavity. This method is faster and more efficient, but it can only be used for metals with low melting points that do not damage the furnace or the plunger. In cold chamber die casting, the molten metal is ladled from a separate furnace into a chamber, and then a plunger pushes the metal into the die cavity. This method is slower and less efficient, but it can be used for metals with higher melting points that would damage the furnace or the plunger in hot chamber die casting.

Hot Chamber Die Casting

Cold Chamber Die Casting