Metal 3D Printing Powder Process from 6K Emits Less CO2 by up to 92 Percent

Massachusetts-based 6K has promoted the environmentally friendly nature of its metal production process, UniMelt. Now, the startup is backing up its claims with hard data. The results of an independent lifecycle assessment (LCA) by Foresight Management has shown that, when producing nickel powders, UniMelt requires 91 percent less energy and emitted 92 percent less CO2 than traditional powder making processes.

6K Additive is the 3D printing materials wing of 6K, which also develops materials for energy storage. These seem like disparate divisions, but due the potential crossover between additive manufacturing and battery production, they may not be as divided as they might seem. Regardless of any overlap, however, the UniMelt process is described as less energy intensive and, therefore, less carbon intensive for producing metals for both applications. The system uses a microwave production-scale plasma process to generate metal powders in less than two seconds. This includes nickel 718/625, titanium64 grade 5/23, copper 18450/GRCop, stainless steel 316/17-4, and refractories such as tungsten and tantalum.

Now, sustainability and energy firm Foresight Management has validated 6K’s technology. The Grand Rapids, Michigan-based company performs LCAs on products to determine their impacts on the global ecosystem. To do so, Foresight relies on primary and secondary data along with GaBi brand LCA software, resulting in data related to the environmental impact of sourcing, refining, and processing. The firm determined that, in its processing of nickel and titanium, UniMelt is significantly less harmful than other methods for producing metal powders, including gas atomization and other forms of plasma atomization.

“This is a cradle-to-end user assessment of the UniMelt technology. We studied all known industrial processes from raw material acquisition and processing up through manufacturing and customer distribution,” explained Brad Van Valkenburg, sustainability manager at Foresight. “This assessment focused on nickel and titanium powders, both of which saw significant advantages when made using UniMelt process. The nickel results showed the UniMelt required 91% less energy and reduced carbon emissions by 92% and the titanium results showed the UniMelt required at minimum, 74% less energy and reduced carbon emissions by 78%.”

Frank Roberts, 6K Additive president, said, “This assessment goes a long way in revealing how the UniMelt process exceeds traditional metal powder processing in environmentally important ways, while also pointing to the inefficiencies of atomization that currently plague AM material production. Sustainability is at the core of who we are at 6K Additive and providing our customers with quantifiable numbers related to the environment helps them move closer to zero carbon manufacturing with AM.”

This is a crucial breakthrough in the world of material processing at a time when resource use most needs to be limited. Numerous sources have concluded that we have less than 10 years to cut greenhouse gas emissions by at least 45 percent, while intensive agriculture and habitat destruction has resulted in biodiversity loss at a rate of 100 to 1,000 times that of the background late. These dual threats would result in total ecosystem collapse for the planet. Meanwhile, humanity has essentially reached peak resource use.

The 6K UniMelt system. Image courtesy of 6K.

It is therefore admirable that 6K has developed such a process, but what makes it all the more exciting is the possibility that UniMelt could be used to recycle existing metal parts. In 2020, the company was awarded a Phase II SBIR grant from the Defense Logistics Agency to recycle scrap metal into quality powders. If such initiatives could be expanded more significantly, it could be possible to reverse some of the damage done to the planet while still maintaining some semblance post-industrial life.

6K will link to the LCA report in the near future. In the meantime, potential partners wishing to learn more about UniMelt can visit the company’s website.