Permanent Mold Casting
The Permanent Mold Process
Permanent mold casting is a cost effective approach to today’s requirements for near net shape castings. Because of its flexibility and design freedom, permanent mold has become a basic foundry process and should be considered as a readily acceptable alternative casting method for components made from sand castings, welded assemblies, forgings, investment castings, and even complex configurations machined from bar stock.
The Permanent Mold process utilizes a metal casting die in conjunction with metal or sand cores, where applicable. The basic casting sequence is as follows: The Metal Mold is preheated prior to production to elevate the mold temperature to operable conditions. The mold, consisting of two or more parts, is then assembled and closed. Molten metal is introduced at the top of the mold with steel cores, if present, being removed shortly thereafter. After solidification, the mold is opened and the casting ejected. The mold is reassembled and the cycle repeated.
Design Data and General Information
Permanent Mold, also referred to as gravity die casting, has several advantages over other processes.
ALLOYS – Aluminum Bronzes, Yellow Brasses, Silicon Brasses, Copper, and Aluminimum.
WEIGHT – 1 ounce to 20 pounds
TOLERANCES – +/- .005 possible in production on some dimensions if less than 1″, +/- .010 would be a more practical tolerance and less costly to maintain. Tolerance of +/- .010 applies on dimensions 1″ to 6″. Dimensions greater than 6″ can be held to +/- .015.