Copper-Nickel Alloys for Military and Defense

The pumps and valves on aircraft carriers and submarines are not like those in manufacturing equipment and machinery. The first difference is that aircraft carriers and submarines require a variety of specialized systems to operate effectively and safely. The second difference is that most of their pumps and valves – which are constantly exposed to saltwater and varying temperatures – need to stay in service for the lifetime of the vessel, which can range from 25 to 30 years.

Producing parts that can resist corrosion while maintaining operational integrity and safety comes down to the alloy and the production quality. C96400 is a copper-nickel alloy known for its excellent resistance to corrosion, particularly in seawater and other marine environments. It is commonly used by the military and defense industries for pump components, valves and fittings that are exposed to seawater and other corrosive environments.

Stainless Foundry & Engineering has produced pump casings and valve bodies using C96400 for decades. We are continuously improving our processes as our work with military and defense customers grows. Experts from the metallurgy, engineering, manufacturing and quality teams work together to ensure each part meets customer requirements and is built to last.

Perfecting the Pour

The combination of copper and nickel in C96400 provides the alloy with a good balance of strength, ductility and resistance to corrosion, making it suitable for a wide range of demanding applications.

Copper and nickel are soluble within each other, making the pouring temperature very specific. Precise pouring is critical for protecting the microstructure, preventing defects, and achieving a balanced fluidity. SF&E engineers have adopted practices to prevent oxidation and contamination of the melt, as well as adding particular elements to enhance the weldability of the alloy.

Maintaining tight control of process parameters such as time at temperature, composition, and properties is crucial to produce sound castings. SF&E engineers develop, test, and refine all internal procedures to ensure the pour is successful.

Quality Control

One way to ensure long-term reliability of a part is non-destructive testing (NDT) capable of detecting flaws on the surface and subsurface that standard methods might miss. Where visual inspection detects obvious surface defects like cracks, discoloration, surface irregularities, and deformation, NDT utilizes different technologies to inspect castings for porosity, leaks, inclusions, and wall thickness.

SF&E and our trusted partners inspect and certify every high specification casting using NDT methods, including:

Ultrasonic Testing (UT) – to detect internal flaws like cracks, voids and inclusions. UT provides precise measurement of material thickness and defect depth and is applicable to a wide range of component sizes and shapes.
Radiographic Testing (RT) – to detect internal defects such as porosity, inclusions and cracks, particularly in complex or thick-walled components.
Liquid Penetrant Testing (PT) – to detect surface-breaking defects such as cracks, porosity and leaks. PT is highly sensitive to fine defects.
Magnetic Particle Testing (MT) – to detect surface and slightly subsurface defects like cracks, seams and inclusions in ferromagnetic materials.

The choice of NDT method depends on the specific application and customer requirements.

Photo Finish

Some parts made out of C96400 require machining to achieve the necessary dimensional accuracy, surface finish and functional features that the casting process alone cannot provide. Machining ensures that the castings meet the high standards required for their intended applications, particularly in industries like military and defense, where precision and reliability are paramount. The specialized machining services at SF&E, which include CNC machining services equipment, software solutions, and trusted approved partners, enable us to finish parts with intricate geometry and detail while maintaining accuracy.

SF&E possesses the knowledge, processes, and facilities to support growth in the military and defense markets. We have sought out a strategy to ensure our alloys and processes can support the needs of the industry and its high precision complex parts. If you would like to learn more about our capabilities in these critical industries, contact us today.

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