Removal of tungsten contamination in titanium powderNo other seem to be able to do that. That should give us another important edge with the aerospace industry.
Interesting one, taken from this April 2021 news release:
PyroGenesis completes NexGen metal powder production line - 3D Printing Industry April 2021
The company has ramped up the commercialization of its patented Plasma Atomization Process in recent years and accelerated its growth strategy to deliver notable R&D developments, including the removal of tungsten contamination from its materials and the launch of its NexGen system. PyroGenesis eliminates tungsten contamination in metal additive powders - 3D Printing Industry
March 2020 ... PyroGenesis, a manufacturer of spherical metal powders using patented plasma processes, has announced that its additive manufacturing materials are officially free-from tungsten.
Known as “the Devil particle,” tungsten is a contaminant of metal powders, causing imperfections and concurrent weakness in a 3D printed part. Tungsten contamination has caused catastrophic part failures in the past, and is a major concern for the aerospace industry.
“This is a significant development in powder production,” comments P. Peter Pascali, CEO & President of PyroGenesis, “What is noteworthy is that within a few short months of having been made aware of this problem, by significant players in the industry, PyroGenesis was able to find an answer.”
Nature of “the Devil Particle”
Tungsten has the highest melting point of all discovered elements and, as Pierre Carabin, Chief Technology Officer of PyroGenesis, explains, “Since the melting point of tungsten is higher than that of titanium, it does not melt during the AM printing process.”
The result, then, is a cluster of solid tungsten particles within an otherwise conformal 3D printed titanium part.
“Tungsten inclusions,” adds Carbin, “can become preferred sites for crack initiation. This has led to catastrophic failures and is clearly unacceptable, particularly in the aerospace industry.”
The source of contamination
Also the heaviest known element, tungsten has exceptional hardness and high density, making it a valuable ingredient in alloys used to make military armaments. It is used to make filament in light bulbs, the nib of ballpoint pens, rocket nozzles and more.
The heavy-metal’s versatile application is also the reason why it can be found contaminating metal powders that would otherwise be free of its presence.
Plasma nozzles used in the powder synthesis process often contain traces of the element. Therefore, PyroGenesis’ solution was to rid their nozzles of tungsten.
PyroGenesis’s plasma answer
Pascali explains, “We know of no other plasma atomization process (using DC torches) which uses tungsten free nozzles,”
“PLASMA TORCHES WITH TUNGSTEN NOZZLES ARE AT HIGH RISK OF HAVING TUNGSTEN INCLUSIONS IN THEIR POWDERS. WE NO LONGER HAVE THAT RISK.”
Additionally, all titanium powders produced by the company are screened for tungsten content, ensuring the quality of the material for its customers.
“This not only underscores PyroGenesis’ ability to quickly find solutions to complex issues,” adds Pascali, “but how these solutions can lead to economically valuable alternatives, and open the door to addressing this need with potential clients.”