EngineeringClicks

3D Printing with Metal Powders

Metal additive manufacturing (AM) has been steadily gaining traction in the manufacturing industry. At present, there is a big focus on advanced aerospace, medical and military products. There is a drive to reduce the cost of metal powders in order to open up the technology to a larger portion of the manufacturing industry. There are numerous metal printing technologies available, and the vast majority make use of metal powder. Some of the more common 3D printing machines are listed in the following section.

Different types of 3D metal printers

How is metal powder made?

Metal powders are the most superior metal 3D printing material, as they allow highly irregular designs to be manufactured with ease and allow the simplification of previously complex assemblies. 

Metal powder is made in 3 main processes as listed below. All of these processes are a form of gas atomisation. 

Characteristics of metal powders

Metal powders are characterised by their particle size distribution as this will determine the minimum layer height that is achievable  The particle size, purity and shape are very important factors in determining the quality of a powder. The more spherical and contaminant free the particles, the higher the quality of the powder.

It must be noted that the mechanical properties of parts made with powdered metals in a laser sintering or laser/electron beam melting processes are not as good as the base material. 

The final strength achieved will depend on the process being used. However, the strength of many 3D printed metal parts can be compared to that of cast parts. It should also be noted that many high stress components are made using the metal powder process and thus the mechanical properties achieved are often ‘good enough’ for the application they are being designed for. In all cases, accurate mechanical properties must be determined by doing tests. 

Grade of metal powders

Almost any metal can be atomised for use in metal additive manufacturing machines. A comprehensive list of suitable materials can be found here. Some key metal groups and their metal powders are listed below:

Titanium

Cobalt

Steel

Nickel

In conclusion

The range of machines making use of metal powder for 3D printing is continuously increasing, thus opening up a multitude of new applications. With improved and optimised manufacturing processes, the price of the powders used in these machines will continue to fall. Furthermore, with improvements in the manufacturing processes, the mechanical properties of these powders will approach that of forged materials.


If you’d like to read more about using metals in 3D printing, download the free guide from Matmatch: The Comprehensive Guide to Metal 3D Printing