From high priced specialty to widely available commodity
For decades metal powders have been widely used in powder metallurgic (PM) processes such as press sintering. Today, annual volumes of powder feedstock for PM are in the range of multiple million metric tons. Mostly iron-based alloys are used to produce high-volume low-cost parts for the automotive, defense, machine and consumer goods industry. Besides low-cost iron parts, PM is used to process unique materials impossible to make with melting or forming technologies. One wide-spread material from this group is tungsten carbide (WC) used for cutting tools.
The powder for PM processes is mostly non spherical and manufactured in high volumes by mechanical milling or water atomization. In contrast, powders for Additive Manufacturing technologies have much higher requirements towards particle shape and surface as well as particle size distribution compared to PM powders.
The most common AM technologies are Laser and Electron Beam Powder Bed Fusion. The PBF systems use a blade, rake or brush to apply the powder on the production bed. To achieve an even and dense layer with this application process, the powder needs to have a certain flowability and particle size distribution. Otherwise powder agglomeration, uneven spreading or blockage of the powder supply may occur. Therefore spherical, gas atomized powder in a particle size distribution between 20 – 120 µm is commonly used. These high requirements, in combination with comparatively low volume demand of high-cost alloys, made an uninteresting market for the major powder suppliers in the beginning of Additive Manufacturing. Until 2016 the market of AM powder was dominated by small specialized suppliers such as AP&C, LPW and TLS in addition to the powder sold directly by the machine OEMs. The low volumes and low competition resulted in extremely high PBF feedstock cost of 10 to 20 times the cost per kg compared to stock material.
With an increase of installed machine base and production volumes, the powder demand grew significantly over the last years. Starting in 2015/16, large powder manufacturers such as HÖGANÄS, VOESTALPINE and SANDVIK entered the market with products specifically targeted at AM customers. Due to these developments the powder prices have been decreasing over the last decade by more than 50%. Furthermore, more and more AM users opted to cut out the middleman, the metal AM system supplier, to avoid the hefty price mark-up and bought directly from the powder supplier.
Today, gas atomized AM powder can be sourced at 5 to 10 times the cost of stock material. Additionally, upcoming machine technology, for example BJT, use alternative powder application mechanisms. This lowers the requirements towards particle shape and enables the use of cheaper non-spherical powder. For high-volume applications, this promises powder prices equal to and even below the price of stock material. In regulated industries such as aviation or medical the high demand regarding quality, certification and traceability of feedstock, however, will most likely always result in powder cost that is significantly higher than stock material.