Melting vs. Sintering Processes (Metal)

Another way to separate the different metal processes is whether the printing process results in a fully-melted part or if a subsequent sintering step is required. Sintering is the process of fusing particles together into one solid mass by using a combination of pressure and heat without melting the materials.

The printing process forms a so-called green part that consists of metal particles that are held together with a binding agent. This green part, which is fragile and needs to be handled carefully, then undergoes a subsequent sintering step to remove the binder in order to form a fully dense part. During sintering, the part undergoes a shrinkage which is still hard to predict and limits the freedom of design. 

You can find selected melting- as well as sintering AM processes below.