THE MATERIALS FOR ADDITIVE MANUFACTURING ARE MANY AND SUITABLE FOR DIFFERENT PURPOSES
Additive manufacturing materials, what are they?
Additive manufacturing materials are virtually identical to traditional alternatives, while others have different properties. Some 3D printing materials have a chemical composition that is identical or similar to a bar material but there is not always a certainty that they will match.
The number of metal alloys available for additive manufacturing, while still less than polymers, is increasing dramatically. Today, considering all the techniques available, the following alloys can be used: Stainless Steel, Tool Steel, Hot Work Steel, Aluminum Alloys, Titanium Alloys, Nickel Alloys, Cobalt-Chromium Alloys, Silver, Bronze, Copper Alloys, Brass and Tungsten.
Today DMLS/SLM technologies are able to laser sintering metal components with a density that is close to 100%. This is a very important characteristic to be considered for subsequent mechanical processing to obtain the desired finishes and tolerances. In addition, a porous material could compromise the correct functioning with the creation of micro-fractures inside the piece, causing the component to break.
Materials for additive manufacturing: processing
The solidification phase of the material during the process takes place very quickly compared to traditional techniques. The plant allows to obtain small grains of powder, obtaining a uniform distribution in the printing area. In this way it is possible to obtain better mechanical properties of the material. For example, as is the case with Ti-6Al-4V in Additive Manufacturing.
Metals used for Additive Manufacturing have a high cost. The least expensive are steels and aluminum alloys. Titanium alloys, on the other hand, are much more expensive. The others instead are placed in the middle of the previous ones.
However, prices are always subject to variation and over time, the more the technology becomes established, the more they will drop. This decrease is already happening and compared to a few years ago the cost has been reduced a lot.
Two families of additive manufacturing materials
Additive manufacturing materials can be divided into 2 families: metals, previously described, and polymers.
Polymers guarantee lower costs both in terms of purchase of the material itself, and in terms of printing technologies, but certainly metals offer higher performance. It is possible to print thermoplastic polymeric materials, polyamide (Nylon) filled with carbon fiber or glass fiber and elastomers.
