Material selection is one of the most crucial decisions made in the design, manufacture, and application of large structural components. Castings and forgings are two alternatives for large structural components.
Casting and forging are two very different manufacturing methods. There are many important factors to consider when selecting the best process to use for the manufacturing of your product, including: Material Type, Product Strength, Net Waste, Temperature Sensitivity, Level of Detail in Finished Product, Tightness of Tolerances and so on.
Casting Process and Consideration
Casting: Heat up metal until it turns into a liquid soup and pour it into a mold. Let it cool off, remove it from the mold (or break the mold), and you got your casting.
The advantages of casting include:
1. No real upper size limit in casting weight
2. Large range of alloy choices
3. As forgings remain solid, custom alloys are far more difficult to get into production whereas with casting, alloys including Chrome, Nickel and Moly can be added at the molten stage.
4. Tooling is often less expensive than forge dies
5. Smaller production “runs” required
6. Complicated/complex parts are no problem
Forging Process and Consideration
Forging: Heat up metal until you you can shape it with force, force it into shape by hammering or pressing it into something, let it cool, and you got your forged piece.
The advantages of forging include:
1. Generally tougher than alternatives
2. Will handle impact better than castings
3. The nature of forging excludes the occurence of porosity, shrinkage, cavities and cold pour issues.
4. The tight grain structure of forgings making it mechanically strong. There is less need for expensive alloys to attain high strength components.
