Metal powder for additive manufacturing and 3D printing

If you wonder “What is additive manufacturing powder and 3d printing”, we hope this page will work as a brief introduction.

Additive manufacturing (AM) – 3D printing – with metal powder is a fairly novel way to create parts that would be impossible to manufacture with conventional machining or casting. A metal powder 3D printer works with fine powdered steel or powder made of other metals. 

Metal powder processes can be used for complicated, lightweight parts for aerospace and automotive applications. Many industrial components such as machine parts and tools can be produced from metal powder, also in high strength versions. Other examples of metal powder products are injection molds, medical implants and watches.

It is difficult to say which is the most popular type of powder manufacturing. In the following we are describing some common technologies. Some use layered 3D additive manufacturing, other use powder manufacturing techniques such as pressing or injection.

Additive manufacturing (AM) or 3D printing is a technology that creates objects by joining material layer on layer. When working with metal powder, the most suitable material is gas atomized metal powder. It has the right properties, shape and size distribution for the powder particles.

A common additive manufacturing method is to use a laser to melt the powder into the desired shape. The machine’s build chamber is filled with a bed of metal powder, which is then sintered or melted by the laser beam. 

The build chamber is lowered after each pass of the laser and more powder is added. The process is repeated until the part is finished. One such technology is laser-powder bed fusion (LPBF).

SSAB is a metal powder supplier focusing on gas atomized steel powder. With this material, the properties of high-strength steel can be transferred into any complex shape by additive manufacturing – 3D printing. This will give new opportunities to design and 3D print steel components with high strength, impact toughness and hardness.

Another technology for additive manufacturing with metal powder is directed energy deposition (DED). This AM technology uses a laser, plasma or an electron beam to melt the metal when it’s deposited from a nozzle. The nozzle moves according to the shape defined by the CAD file. DED is used to manufacture metal parts or to add metal to existing parts, for example to perform repairs.

Solid steel pieces can be created from metal powders using hot isostatic pressing (HIP). The powder is placed in a sealed container which is heated to just below the melting point of the metal. An inert gas such as argon is used to pressurize the metal with a pressure of around 100 MPa or higher.

This hot and pressurized process reduces the porosity of the material and creates a practically solid component.

MIM is a process where metal powder and a binder are combined to produce a material that can be shaped using injection molding techniques. The metal particles in the molded sections are then heated under pressure – sintered – to remove the binder and create a solid metal part.

MIM can create products with highly accurate tolerances and an improved surface finish. It also allows for more complex designs. Small parts that are challenging to manufacture using other techniques are often made with MIM.

To create this type of fine powder, metal is melted and then poured into an atomizing chamber, where high-pressure inert gas is injected into the stream of molten metal, transforming it into a powder comprising rounded particles. The powder is then sieved into different fractions to suit different production technologies.