Types of metal AM

There are a growing number of metal AM technologies available to the market place.
What are the main features of each?

5 Main Technologies


Powder Bed Fusion (PBF) – using either a laser or electron beam to melt metal powders that have been spread out across a unform layer.


Directed Energy Deposition (DED) – the largest group of technologies each loosely based on a form of welding.


Material Extrusion (ME) – using 2D inkjet printing technology to print with a binding fluid onto a bed of metal powder.


Binder Jetting (BJ) – using 2D inkjet printing technology to print with a binding fluid onto a bed of metal powder.


Solid State Forming (SSF) – any technique that forms a metal object without any melting, through direct contact and the metal on metal interaction.

Under these five categories are various process technologies and each rely on a particular type of materials behaviour. These are melting, sintering on forming.

Melting or Sintering

Generally metal AM involves either melting or sintering of a feedstock material, and this is either accomplished directly in the process, or as a post-processing step after the 3D build. The exception is Solid Sate Forming technologies, such as Cold Spray.


Whether using PBF or DED the metal feedstock, powder or wire, is fully melted when producing the 3D object.


Both ME and BJ rely on and de-binding step and heat treatment to sinter the 3D parts into solid metal.


In these very specialist processes that do not require any melting, or do not use sintering to consolidate parts, but instead rely on massive amounts of plastic deformation to bond metal together are referred to as Solid State Forming.

Laser Powder Bed Fusion

The first popularised metal AM technology that found initial success in applications in the dental sector and development of injection mould tooling. After 2010 the focus of much development in the aerospace and medical sectors.

Electron Beam Powder Bed Fusion

This high energy technique made an immediate impact in the medical sector for the development and production of orthopaedic implants with osseointegration features. Later also becoming the most important process for high temperature alloys, such as TiAl used in aerospace.

Blown Powder Laser Deposition

Perhaps one of the earliest forms of metal AM, developed from laser cladding used for resurfacing and hard-facing other metal parts. This technique has experienced only a small amount of adoption, though there has been growing success with hybrid AM-CNC machining systems.

Wire Laser Deposition

The only real difference in this technique to blown powder laser deposition is the fact that it relies on metal wire as the welding feedstock. It is now becoming a popular process to investigate large scale metal AM.

Wire Arc Deposition

This has become the mainstay of the deposition technologies relying on MIG/TIG and plasma arc style welders attached to the end of robot arms. These systems now range in size and offer a very higher degree of flexibility.

Materials Extrusion

These are hybrid Fused Deposition (FDM) Moulding systems, the most commonly associated with the term 3D printing. These system have been adapted to work with metal filled polymer filaments and require parts to go through de-binding followed by sintering.

Binder Jetting

Another powder bed process where instead of fusion parts are printed by jetting a binder solution into the metal powders which is then cured to forma green part. After removing any excess powder the process requires parts to go through de-binding followed by sintering.

Green Machining

In this almost unique process solid blocks of green material are either formed by Binder Jetting or Materials Extrusion and then subsequently machined to the final profile. After completing the final machining operation parts go through de-binding followed by sintering.

Solid State

In Cold Spray AM parts are formed when metal powders are introduced into a stream of supersonic gas tat forces the particles to smash into a substrate and deposit as solid metal. In Ultrasonic AM friction induced in the vibrating tip of a consumable metal rod bonds the metal to the substrate.

M A M Solutions has experience to guide your business on the selection of the right AM technology, so contact Martin McMahon today.