90/10, an alloy of 90% copper and 10% nickel, contains small yet important additions of manganese and iron that increase its overall strength and resistance to corrosion.
Corrosion Properties of 90/10
90/10 cupronickel is traditionally used in marine environments as it has low rates of corrosion rates in brackish water and seawater, inherent resistance to biofouling, good pitting resistance, high resistance to ammonia stress corrosion cracking, high resistance to hydrogen embrittlement and excellent resistance to stress corrosion and crevice corrosion.
Additionally, the alloy retains its mechanical properties over a wide temperature range, from elevated temperatures down to cryogenic temperatures as low as –300 °F.
The corrosion resistance of 90/10 is due to a protective surface film that forms when the alloy comes into contact with water. The corrosion rate has been shown to be minimal, even in fast-flowing seawater. This oxide layer that forms on the surface makes the 90/10 alloy inhospitable to most marine organisms in slow-moving water.
Machining Properties of 90/10
In industrial and architectural applications, 90/10 has already gained importance as Designers have put its excellent toughness, high ductility, and attractive pink/ white/silver coloration to good use. Its excellent forming and fabrication properties, which enable blanking, drawing, punching, machining, bending, stamping, shearing and forming improve its suitability for a vast range of applications.
The machining properties of 90/10 are very similar to other high-strength, copper-based alloys such as phosphor bronze, nickel silver and aluminum bronze. It possesses adequate strength to survive the pressures experienced in most marine instrumentation and hydraulic systems.
Tests performed on the alloy indicate that it possesses excellent antimicrobial characteristics. It can kill 99.9% of a wide range of organisms, including E.coli, clostridium difficile, MRSA and influenza A (H1N1,) within two hours. This has created a demand for 90/10 in sanitary or hygienic environments in hospitals, nursing homes and kitchens.
- High ductility
- Outstanding corrosion resistance
- Attractive pink/silver coloration
- Easily joined
- Easily formed / fabricated
- Excellent durability
- Oxidation and tarnish resistance
- Proven antimicrobial properties
- Outstanding resistance to creep
Applications of 90/10
The pleasant pink/silver coloration, coupled with its formability, makes 90/10 aesthetically pleasing and a perfect substitute for many stainless steels in the form of door and cabinet handles, push plates, balustrades, handrails, plaques, counter tops, work surfaces, kick plates, sculptures and decorative metalwork. Its resistance to corrosion also makes it suitable for salt water pipes and fittings, marine hardware, heat exchangers, salt water baffles, cooling plants, hot water plants, valve and pump components and flanges, and also for crankshafts, hulls of working boats and propeller sleeves.
Columbia Metals stocks 90/10 cupronickel in the form of sheets, round bars, and hexagons. In the US and in Europe, CN 102/C70600 and CW352H are the most common standards for the alloy. In the UK, it is released to the applicable Defence Standard DEF STAN 02-879 Annex C, which supersedes DEF STAN 02-779.
Nominal Composition (%)
Mechanical Properties (specification minima)
|Ultimate Tensile Strength (N/mm2)
|0.2% Proof Strength (N/mm2)
Weight and Stock Sizes
|13 mm - 70 mm A/F in a comprehensive range
||4’ x 2’ sheets in thickness from 16 g upwards
Download the Specification Sheet for More Information
NB Weight data for guidance only.
This information has been sourced, reviewed and adapted from materials provided by Columbia Metals Ltd.
For more information on this source, please visit Columbia Metals Ltd.