Elmet Is 3D Printing Hypersonic Heat Exchangers From a $4,000-per-kg Alloy

C103 is the hardest part of the problem

Hypersonic vehicles push air so fast it generates temperatures that melt ordinary metals. The heat exchangers that manage those temperatures need an alloy that can survive the heat without oxidizing. C103, a niobium-hafnium-titanium blend, does the job. It also costs up to $4,000 per kilogram and reacts badly with oxygen.

Elmet Technologies, a subsidiary of The Elmet Group, is installing a DMP Flex 350 Triple metal 3D printer from 3D Systems to produce monolithic heat exchangers from C103. The printer maintains oxygen levels below 25 parts per million, typically between 0 and 6 ppm. Ambient air contains roughly 210,000 ppm of oxygen. That gap matters because C103 powder degrades quickly when exposed to oxygen, and at $4,000 per kilogram, any waste is expensive.

Eight years to get the parameters right

Elmet and 3D Systems' Application Innovation Group spent eight years developing print parameters for C103 on the DMP platform. The qualification effort was necessary because C103 requires unusually tight control of oxygen levels during the laser powder bed fusion process. A company cannot simply buy a new printer and start printing critical aerospace parts the next day.

The DMP Flex 350 Triple operates three lasers across a 350 by 350 by 350 millimeter build volume. Elmet plans to print large heat exchangers as single monolithic components. The conventional approach, brazing, requires fabricating individual sections, aligning them, applying filler metal, and running the assembly through a furnace. Each brazed joint is a potential failure point under extreme thermal cycling.

Supply chain resilience is part of the pitch

Refractory metals like C103 pass through a small number of suppliers and fabricators. Elmet is positioning additive manufacturing as a way to reduce that concentration risk. The company describes the capability as localized production for the U.S. defense industrial base.

Elmet is not alone in trying to qualify C103 for additive manufacturing. Velo3D has been working with Amaero C103 powder, and Auburn University's National Center for Additive Manufacturing Excellence confirmed the powder met ASTM standards after heat treatment. But Elmet's installation suggests it believes it is close to production readiness.

Heat exchangers may not grab headlines the way rocket engines do, but they are critical components for hypersonic flight. If Elmet can produce them reliably at scale, it opens a path toward more practical hypersonic systems. That is a meaningful step for both the company and the broader hypersonic industry.