There are more than 400 different alloys available that are based upon copper as the base metal, sometimes incorrectly captioned as bronzes (which are copper-tin alloys) and brasses (copper-zinc alloys). The creation of the Langley Alloys Ltd business can be traced back to the special copper alloys division of High Duty Alloys Limited and has ultimately resulted in a number of unique high-performance alloys. Copper has the best electrical and thermal conductivity of any commercial metal, but careful alloying creates a wider range of competitive properties.
The Hiduron® alloys are cupronickels, so predominantly consist of copper-nickel, meaning that they have excellent resistance to corrosion in seawater, marine and industrial applications. They are strengthened by smaller additions of aluminium and iron, achieving significantly higher strengths than other copper alloys which also improves their wear resistance and anti-galling properties, making them widely used in naval and oil & gas applications. By replacing some of the aluminium and iron additions with manganese, Hiduron 191 has a lower proof stress, but has much greater ductility and toughness. The Hiduron products are the only high-strength copper alloys with a proven record of resistance to hydrogen embrittlement.
Hidurel® 5 is a copper-nickel-silicon alloy. As the alloy additions are relatively modest compared with alternatives, it retains high conductivity, but still achieves much greater levels of strength than commonly available metals such as nickel-aluminium bronze (NAB) and 70/30 copper-nickel. Interesting features include its extremely low magnetic permeability and strong bearing properties making it a strong candidate for many diverse marine applications.
|Alloy||Common Name||Related Specifications||Tensile Strength||Proof Test||Elongation|
|British||European||United States||N/mm2 (ksi)||N/mm2 (ksi)||(%)|
|Hidurel 5||UNS S64700 CuNi2Si||BS B25
||587 (85)||430 (62)||18|
|Hiduron 130||Hidurax Special||DTD 900/4805
||850 (123)||630 (91)||10|
|Hiduron 191||UNS C72420||DEF STAN 02-835
|725 (105)||430 (62)||18|
Hidurel® 5 is a precipitation-hardening copper-nickel-silicon alloy possessing high electrical and thermal conductivity with very good notch ductility and high mechanical strength. Annealing at elevated temperature creates a soft supersaturated alpha-phase structure, before subsequent age hardening at lower temperature precipitates finely dispersed nickel silicide in the matrix. Despite its high strength, the alloy is resistant to hydrogen embrittlement. Resistance to corrosion under marine and industrial conditions is excellent and the alloy has good anti-frictional and bearing properties. With a magnetic permeability of less than 1.001, the alloy is essentially non-magnetic.
Hiduron® 130 is a high-strength cupronickel supplied in the hot worked condition. Aluminium is the alloys key strengthening element in a similar way to Alloy K-500. As these precipitates are formed through a carefully controlled forging process, naturally aged during cooling, no further heat treatment is necessary, making it one of the highest strength copper alloys commercially available. Being a cupronickel, it has excellent resistance to corrosion by seawater and in marine and industrial atmospheres and it is highly resistant to crevice corrosion.
Hiduron® 191 is a medium-strength precipitation hardened cupronickel alloy supplied in the hot worked condition. It contains about 14.5% nickel and 4.5% manganese strengthened by additions of aluminium and iron, which may be refined by controlled small amounts of chromium.
Hiduron® 191 was developed to provide both the corrosion resistance and anti-fouling characteristics of conventional cupronickels but with superior tensile and toughness properties compared to aluminium bronzes. Its resistance to marine corrosion is comparable with that of conventional cupronickels, the combination of tensile strength and toughness is far superior to that available with aluminium bronzes and its properties are largely independent of section size.