CuNi: the steel of maritime AM | VoxelMatters

This text was initially printed in VoxelMatters’ Steel AM Focus 2025 eBook. The total version will be discovered right here.

Within the maritime business, notably within the shipbuilding phase, materials selection is a important consideration. Whereas in industries like aerospace, minimal weight and high-temperature resistance are a prime precedence, within the maritime sector, corrosion resistance and sturdiness are essentially the most important materials properties. It makes good sense: elements on a ship should have the ability to face up to the tough surroundings at sea, together with the corrosive nature of sea water, whereas additionally providing structural integrity and a protracted lifespan.

For these causes, the maritime business has gravitated in the direction of a comparatively small choice of steel sorts, together with metal (ship hulls are constructed from metal, as an illustration), aluminum (used for superstructures and non-structural elements to maximise gasoline effectivity), Inconel (used for propeller blades and scrubbers) and different superalloys. Within the rising maritime AM subsegment, a small variety of particular alloy sorts have risen to the highest and chief amongst them are copper–nickel alloys (CuNi).

CuNi alloys are already properly established within the maritime business. The metals, identified for his or her glorious corrosion resistance and low macrofouling charges, have varied functions in offshore, naval and shipbuilding segments, together with desalination programs, piping, warmth exchangers, condensers and extra. Whereas most CuNi components in maritime are manufactured utilizing extra conventional strategies like casting, additive manufacturing is more and more changing into a viable possibility as firms within the AM business develop and validate CuNi for varied steel 3D printing processes. That is notably essential contemplating that forged CuNi alloys will be suffering from challenges like cracks and porosity, which necessitates rework, in the end driving up prices and lead instances.

With the ability to additively manufacture CuNi components presents shipbuilding and naval organizations a number of advantages, together with unlocking extra speedy manufacturing instances (eliminating the necessity for tooling), lowering reliance on giant stock shares, simplifying provide chains and manufacturing extra effectively designed elements. On prime of that, AM permits extra sustainable practices by the minimization of fabric waste and extra localized manufacturing, which reduces emissions related to logistics. Applied sciences like directed power deposition (DED) are additionally making it doable to restore current elements additively, which has advantages relating to sustainability (extending the lifespan of huge components) and value. 

Inside the AM business, solely a small variety of firms presently provide copper-nickel alloy supplies. It’s value mentioning, nonetheless, that although the group is small, it’s rising, with new CuNi merchandise being launched and validated previously 12 months. This latest progress simply goes to indicate how the steel AM business is recognizing the large potential of maritime as an AM adopter. 

The first CuNi alloy developed particularly for maritime additive manufacturing was launched in 2022 by 3D Techniques. The fabric, CuNi30, was developed for the corporate’s DMP Flex 350 platform by a collaboration with HII’s Newport Information Shipbuilding division. The fabric reportedly ends in components with superior density and mechanical properties in comparison with forged components—all with out the necessity for tooling—and demonstrates stability over a broad vary of temperatures (from 400 °C to -270°C). These properties make CuNi30 appropriate for a variety of maritime (and adjoining) functions, like ship pipe fittings, valves and pumps; off-shore oil and gasoline elements; chemical and nuclear tools; and even cryogenic programs.

The introduction of the fabric enabled Newport Information Shipbuilding to take advantage of the advantages of LPBF for its low-volume, high-mix half necessities. On the time of the fabric launch, the top person anticipated a dramatic 75% discount in lead instances and decrease stock prices in comparison with their typical casting workflows.

Because the launch of 3D Techniques’ licensed CuNi30, German 3D printing chief EOS has additionally developed its personal CuNi30 powder for LBPF, with a nickel content material of 28–32%, and small quantities of niobium, iron and manganese. The copper-nickel alloy, which launched commercially in early 2024, presents a variety of properties appropriate for maritime functions, similar to glorious energy with as much as 700 MPa in heat-treated horizontal builds, and ductility with round 510 MPa UTS and greater than 20% elongation. 

The alloy was developed and validated in cooperation with Philips Federal and Austal USA for the Submarine Industrial Base (SIB). Particularly, EOS developed the fabric with the purpose of “assuaging provide chain pressures” on conventional forged elements for the two+1 Columbia and Virginia Class submarine platforms for the US Navy. The AM-grade materials conforms to UNS C96400 specs in ASTM B369-09 and presents the identical stage of corrosion resistance as forged CuNi elements with out the manufacturing woes. When it comes to software, EOS’ CuNi30 is right for a variety of maritime elements, together with pumps, impellers, submarine seawater consumption valves, high-pressure piping and propulsion {hardware}.

In 2024, ADDMAN Group, by its Harbec enterprise unit, entered right into a partnership with the US Navy to qualify CuNi elements for submarines. This qualification effort is in the end geared toward establishing AM as a viable manufacturing methodology for CuNi components with the intention to speed up procurement cycles and enhance general half high quality. For the US Navy particularly, 3D printed CuNi might meet its “2+1” submarine manufacturing targets.  

Within the final 5 months, no less than three new efforts to qualify copper-nickel alloys for additive manufacturing have arisen with the purpose of furthering AM functions within the maritime and protection (particularly naval) sectors. Australia-based AML3D, a specialist in Wire Additive Manufacturing (WAM) introduced in Could that it had signed a $1.01 million buy order with BlueForge Alliance, a nonprofit integrator that helps the US Navy’s Submarine Industrial Base, to develop and qualify CuNi alloys for protection functions. This follows a profitable characterization of a CuNi alloy in 2023, which was a part of  a US Navy submarine qualification program.

In the identical month, UK-based steel AM firm Renishaw revealed it had teamed up with Austrian steel powder producer Metalpine to develop and qualify CuNi powders to allow a “main European naval power” to provide alternative components in-house. Particularly, the companions developed course of parameters for CuNi 10 (which consists of 90% copper and 10% nickel) and CuNi 30 (70% copper, 30% nickel). 

“With these exact settings we’ve got overcome the fabric’s challenges, guaranteeing high-quality, sturdy components that may face up to harsh marine environments,” stated Alex Garcia, AM Design and Functions Engineer at Renishaw. “This optimization enhances half energy and longevity and ensures constant outcomes, permitting our naval buyer to fabricate components that carry out reliably beneath powerful circumstances.” 

Extra not too long ago, American steel AM firm Velo3D introduced the event and qualification of a CuNi alloy for its Sapphire 3D printer collection. The event, formalized by a $6 million contract, will help the US Navy Maritime Industrial Base within the restore of important ship constructions and elements. Notably, Velo3D says this contract will make it the primary American OEM to qualify CuNi for its domestically developed 3D printers, together with the large-format Sapphire XC 3D printer. 

The CuNi growth course of is being led by Velo3D’s workforce in Fremont, California, which can develop course of parameters for a powder equipped by a home, brazenly sourced steel powder supplier (a vital consideration with the intention to keep provide chain independence for the US Navy.”

Finally, the event of CuNi alloys for AM processes and platforms will solely profit finish customers from the maritime and naval sectors, as they can’t solely leverage the advantageous properties of the fabric, but additionally the inherent belongings of AM, together with design freedom, manufacturing agility and materials effectivity.