Which is Better – Forging or Casting?

Summary:

Casting vs forging is a popular debate, many experts have their own views for the same. Though the truth is that forging is better for simpler designs and small parts but for more intricate designs casting is the better option.

Casting:

The process in which the metal is first heated to melt it and then while it is in molten state it is poured into a mold or vessel to create the required shape. The solidified part can also be called as a casting, which is taken out of the mold to complete the process. Casting materials are usually made of metals of various cold settings such as concrete epoxy, plaster or clay.

Castings are used for making wear parts and components that are complicated, huge, intricate or in short unsuitable for the forging process. Casting is a 6 millennia old process and the oldest known cast is that of a frog from 3200 years ago.

Types of casting include expendable mold casting and non-expendable mold casting

Expendable mold casting includes types like sand casting, plaster mold casting, shell casting, investment casting, waste molding of plaster, evaporative pattern casting, lost foam casting, full mold casting.

Non-expendable mold castings include permanent mold casting, die casting, semi-solid metal casting, centrifugal casting, and continuous casting.

Advantages of casting:

1. No size limitations of size and weight- this means that the size and weight of the cast can be as per our desires and wishes.

2. A large number of choices in alloys – High-quality casting can be made by using different alloys.

3. Chrome, Nickel, and Moly can be added to the molten mix to make custom alloys that aren’t possible in forging.

4. Complicated/complex parts can be made easily.

Forging:

Forging is a process in which the metal is shaped using forces of tools like a hammer or a die. It can be segregated into types depending on the temperature it is performed at. It is one of the oldest metalworking processes that was performed by a Blacksmith on an anvil. The forged metal is usually stronger and more reliable than casting due re-crystallization grain refinement. There are many forging manufacturers in India who prefer it for simpler designs.

In modern times, it is done with powered hammers that are powered by either compressed air, electricity, hydraulics or steam. The forging process can be attained at different temperatures and the temperature is performed at defines its name. Thus cold forging is done at lower temperatures as compared to warm or hot forging.

Another way of classifying forging is by basing it on the arrangement of dies i.e. closed die forging and open die forging as used by the forge company. And another way if classification would be to classify it by considering the forging equipment it utilizes. For example hammer forging, press forging and hydraulic press forging which are self-explanatory.

Advantages of forging:

1. Usually tougher, harder, stronger than alternatives

2. Forged metal takes impact better than its counterparts

3. Forging eliminates the occurrence of porosity, cavities, and cold pour and shrinkage

4. The Re-crystallization process makes the grain structure tight that offers better mechanical strength. Also, it utilizes less expensive alloys to high strength forges.

5. The tight great structure also offers unparalleled grain resistance.