Elmet 3D Prints Hypersonic Heat Exchangers That Brazing Can't Match

Why Hypersonic Heat Exchangers Are So Hard to Build

Hypersonic vehicles push air to temperatures and pressures that cook ordinary materials. The heat exchangers that manage those flows need walls so thin and internal geometries so complex that conventional manufacturing simply cannot reach them. Brazing individual sections together introduces joints, and those joints become failure points under extreme thermal cycling.

Elmet Technologies, a subsidiary of the Elmet Group, is taking a different route. The company is installing a 3D Systems DMP Flex 350 Triple metal 3D printer to produce heat exchangers as single monolithic components. No brazing. No alignment steps. No filler metal. Just one digital file turned into a solid part.

The DMP Flex 350 Triple in This Context

The DMP Flex 350 Triple uses three lasers across a 350 x 350 x 350 mm build volume. For Elmet, the critical feature is not the size. It is the oxygen control. The printer keeps oxygen below 25 parts per million, with typical levels between 0 and 6 ppm. Ambient air contains roughly 210,000 ppm of oxygen.

C103, the niobium-based refractory alloy Elmet plans to use, is extremely oxygen-sensitive. Even small amounts of contamination degrade its mechanical properties. Low oxygen levels also let Elmet reuse powder across multiple builds without losing material performance. That matters because C103 powder costs up to 4,000 dollars per kilogram.

From Prototype to Production in Eight Years

Elmet has spent eight years developing this material-machine combination. That timeline reflects the reality of refractory metals in aerospace. Qualification is not a quick process. The company needs data that satisfies both its own internal standards and the agency certifications required for flight hardware.

The stated goal is production entry in 2026. That suggests Elmet believes the qualification groundwork is largely complete. The DMP Flex 350 Triple installation is the final step in moving from lab samples to flight-ready hardware.

Supply Chain and National Defense Angle

Refractory metals like C103 pass through a very small number of suppliers and fabricators. Most are concentrated outside the United States. Elmet is positioning additive manufacturing as a way to reduce that exposure. Localized production of hypersonic components strengthens the domestic defense industrial base, a point the company is making explicitly in its public statements.

The same logic applies to tooling and spare parts. Waiting months for a replacement heat exchanger is not an option when a program is pushing toward flight tests. In-house metal AM shortens that timeline dramatically.

The Bottom Line

Elmet is trying to solve three problems at once: geometry that brazing cannot reach, material properties that conventional processing destroys, and supply chain risk that single-source refractory metals create. Additive manufacturing is the only approach that addresses all three. If the company hits its 2026 production target, it will be a proof point for metal AM in hypersonic applications that the industry has been waiting years to see.