Casting process is the most direct method of producing a product from the chosen material.
Though products in all the three major classes of materials, metals, ceramics and polymers
can be produced by this method, casting of metals is by far the most widely used process.
The basic steps in the casting process are preparation of the material in the liquid state,
transferring the liquid material into a shaping mold, allowing the transformation of liquid
material in the mold into a solid form.
Three-dimensional models can be made accurately enough by RP
methods to evaluate the design process and eliminate interference fits or
dimensioning errors before production tooling is ordered. If design flaws
or omissions are discovered, changes can be made in the source CAD
program and a replacement model can be produced quickly to verify that
the corrections or improvements have been made. Finished models are
useful in evaluations of the form, fit, and function of the product design
and for organizing the necessary tooling, manufacturing, or even casting