Our “Life of a Casting” series follows a cast iron or steel product through the discrete steps of production in a foundry.
Casting is the process of creating metal objects by pouring liquid metal into molds, where it cools and hardens into the mold’s shape. Although the premise is simple, there are many variations in metal casting methods. To take an object from idea to reality, designers must specify the physical and aesthetic needs of the final product, and from there find the simplest way to produce those qualities. The complexity of the design, as well as what stresses the final object must withstand, help determine the metal; how the metal behaves in liquid, solid, and cooling states will dictate requirements for the mold. Good casting design is a matter of knowing all the ingredients and processes involved to get to the final product.
Metalworkers have used the same casting processes for millennia, with the first castings dating back to the 4th century BC in China. Even with this long history, the foundry is a place of development and innovation. In this fourteen-week series we will explore all the steps in making a casting, and what factors influence the choice of method or design, from ancient wisdom to the modern-day advances.
Every week we will feature another stage of the process, exploring:
Patterns are the prototype objects used to create molds. They must be designed to be removed from the mold without disturbing it, as well as with the behavior of the metal while pouring and cooling in mind.
In a variety of ways, the metals used in a set of castings, and the castings themselves can be quality assured. Materials analysis studies the properties and composition of the metal, while both destructive and non-destructive testing looks for shrinkage or casting defects.