How Forgings Compare To Castings

Maple summarizes the following points.

Forgings are stronger.

Low standard mechanical properties (e.g. tensile strength) are typical of P/M parts. The grain flow of a forging ensures strength at critical stress points.

Forgings offer higher integrity.

Costly part-density modification or infiltration is required to prevent P/M defects. Both processes add costs. The grain refinement of forged parts assures metal soundness and absence of defects.

Forgings require fewer secondary operations.

Special P/M shapes, threads and holes and precision tolerances may require extensive machining. Secondary forging operations can often be reduced to finish machining, hole drilling and other simple steps. The inherent soundness of forgings leads to consistent, excellent machined surface finishes.

Forgings offer greater design flexibility.

P/M shapes are limited to those that can be ejected in the pressing direction. Forging allows part designs that are not restricted to shapes in this direction. Forgings use less costly materials. The starting materials for high-quality P/M parts are usually water atomized, pre-alloyed and annealed powders that cost significantly more per pound than bar steels. So What is forging?

 Forging is a manufacturing process where metal is pressed, pounded or squeezed under great pressure into high strength parts known as forgings. The process is normally (but not always) performed hot by preheating the metal to a desired temperature before it is worked. It is important to note that the forging process is entirely different from the casting (or foundry) process, as metal used to make forged parts is never melted and poured (as in the casting process).

Why use forgings and where are Maple used?

The forging process can create parts that are stronger than those manufactured by any other metalworking process. This is why forgings are almost always used where reliability and human safety are critical. But you'll rarely see forgings, as they are normally component parts contained inside assembled items such airplanes, automobiles, tractors, ships, oil drilling equipment, engines, missiles and all kinds of capital equipment - to name a few.