Maritime environments are among the many most demanding for engineered supplies. Saltwater corrodes metallic relentlessly, temperature fluctuations take a look at structural stability, and mechanical stresses from waves, currents, and onboard techniques problem sturdiness. For many years, copper-nickel alloys have been the popular selection for shipbuilding and marine gear resulting from their glorious corrosion resistance and reliability.
From a strategic want
The event of CuNi30 was pushed by a strategic goal: to deal with provide chain bottlenecks attributable to lengthy lead occasions for solid copper-nickel elements. The U.S. Navy’s “2+1 Columbia and Virginia Class submarine platforms” program required another casting technique that would meet efficiency requirements whereas lowering manufacturing delays.
EOS responded by creating a cloth that conforms to UNS C96400 specs in ASTM B369-09, providing the identical corrosion resistance and power anticipated from conventional CuNi alloys however optimized for additive manufacturing. Typical purposes of EOS CopperAlloy CuNi30 embody numerous varieties of marine elements, significantly pumps and impellers.
Based on Ankit Saharan, Senior Supervisor of Metals Know-how at EOS, the venture was fast-tracked to help the Navy’s schedule, leading to a industrial launch simply months after improvement started.
Composition and efficiency
EOS CopperAlloy CuNi30 is a copper-based alloy with a nickel content material of 28–32%, balanced with small quantities of niobium, iron, and manganese to boost mechanical stability and corrosion resistance. The cautious stability of parts ensures excessive ductility even at extraordinarily low temperatures, a vital issue for vessels working in Arctic waters or deep-sea environments.
Mechanical exams reveal tensile strengths of as much as 700 MPa in heat-treated horizontal builds, yield strengths of as much as 560 MPa, and elongations at break exceeding 30% in as-manufactured situations. Even below stress reduction warmth therapy, the alloy retains an elongation of over 20%, making it extremely proof against brittle failure. Its hardness ranges from 75 HRB within the as-built state to 90 HRB after warmth therapy, delivering each sturdiness and machinability.
One among CuNi30’s most spectacular qualities is its capability to retain excessive ductility and mechanical power throughout completely different manufacturing orientations and temperatures.
Typical Mechanical Properties (Warmth Handled, EOS M 290 Construct)
Etched micrograph in as as-manufactured state
Yield Power (Rp0.5): As much as 560 MPa (horizontal)
Final Tensile Power (Rm): As much as 700 MPa (horizontal)
Elongation at Break (A): 22–28%
Hardness: 90 HRB (heat-treated)
Functions for harsh marine environments
Saltwater corrosion poses a continuing menace in maritime engineering, leading to expensive repairs, downtime, and, in some circumstances, catastrophic failure. CuNi30’s nickel-rich composition promotes the formation of a protecting oxide layer, shielding elements from pitting and crevice corrosion. Its resistance to biofouling additionally reduces the necessity for frequent cleansing and upkeep.
The alloy performs constantly even in low-temperature environments, guaranteeing that elements keep their power and toughness in Arctic operations and deep-sea missions. This stability makes CuNi30 equally appropriate for naval protection techniques and industrial marine purposes.
SEM micrograph of EOS CopperAlloy CuNi30 powder.
The properties of CuNi30 make it a wonderful selection for seawater-exposed techniques. It’s already being adopted for submarine elements similar to seawater consumption valves, high-pressure piping, and propulsion {hardware}. As beforehand talked about, it’s equally efficient in pumps and impellers, the place its resistance to each corrosion and particle erosion extends service life in difficult situations.
Further AM purposes embody marine warmth exchangers and condensers, which profit from CuNi30’s excessive thermal conductivity and corrosion resistance, guaranteeing environment friendly warmth switch and long-term reliability. Offshore oil and gasoline infrastructure—the place publicity to saltwater, excessive strain, and corrosive gases is fixed—can use CuNi30 to increase the lifetime of risers, connectors, and subsea fittings.
Additive manufacturing adjustments every thing
Historically, casting copper-nickel alloys for these purposes is gradual and dear as a result of complexity of molds, strict qc, and restricted provider capability. With DMLS, CuNi30 elements may be produced on demand, near their level of use, and with out the necessity for costly tooling.
This shift permits shipyards and naval services to bypass months of lead time, whereas additionally opening up new design prospects. Inside channels, optimized geometries, and weight-reduced buildings—unimaginable with casting—at the moment are possible, enhancing efficiency whereas lowering materials utilization.
CuNi30 is on the market for EOS’s mid- and large-frame techniques, particularly the EOS M 290 and EOS M 400 collection. It’s processed with a 60-micron layer thickness below an argon ambiance, leading to high-density elements with a defect content material of lower than 0.1%. Dimensional change after warmth therapy is often round 0.1%, permitting exact tolerances to be maintained.
Its toughness throughout a large temperature vary is one other standout function. Charpy V-notch exams reveal impression power values of as much as 190 J at -85°C within the as-manufactured state, confirming its capability to face up to shock hundreds in excessive situations.
Processing parameters and gear compatibility
Micrograph of a cultured floor
EOS CopperAlloy CuNi30 is optimized for:
EOS M 290 (mid-frame)
EOS M 400-1 and M 400-4 (large-frame, high-output techniques)
Commonplace Processing Parameters:
Layer Thickness: 60 μm
Inert Fuel: Argon
Recoater Blade: Excessive-Pace Metal (HSS)
Sieve Dimension: 90 μm
Dimensional Change After Warmth Remedy: ~0.1%
A strategic benefit for naval operations
By enabling regional, on-demand manufacturing of vital elements, CuNi30 reduces dependence on lengthy casting provide chains. This not solely hurries up upkeep and new development but in addition strengthens nationwide safety by guaranteeing that important elements may be manufactured domestically and shortly.
As John Harrison, Senior Vice President of World Additive at Phillips Federal, famous, the alloy is “vital in lots of marine purposes and will probably be vital in our efforts to help the U.S. Navy Middle of Excellence.”
Appropriate for the EOS M 290 and EOS M 400 techniques (at 60 µm decision), EOS CopperAlloy CuNi30 is on the market from the EOS on-line retailer in a Pack Dimension of 10 kg for €1.432,40 (about €150 per Kg).
EOS CopperAlloy CuNi30 represents a brand new manufacturing mannequin for the maritime sector. By combining the sturdiness and corrosion resistance of conventional copper-nickel alloys with the design freedom, velocity, and adaptability of additive manufacturing, it affords shipbuilders and naval engineers a robust instrument to satisfy the ocean’s challenges head-on.
