Adding nickel to pure copper can significantly improve the strength, corrosion resistance, hardness, resistance and pyroelectricity, and reduce the temperature coefficient of resistivity. Therefore, compared with other copper alloys, white copper has excellent mechanical and physical properties, good ductility, high hardness, beautiful color, corrosion resistance and good deep drawing performance. Widely used in shipbuilding, petrochemical industry, electrical appliances, instruments, medical devices, daily necessities, handicrafts and other fields, and is also an important resistance and thermocouple alloy. The disadvantage of white copper is that the main added element-nickel is a scarce strategic material, and its price is relatively expensive.
Among copper alloys, white copper is widely used as corrosion-resistant structural parts in shipbuilding, petroleum, chemical industry, construction, electric power, precision instruments, medical instruments, musical instrument manufacturing and other departments because of its excellent corrosion resistance and easy molding, processing and welding. Some white copper also has special electrical properties, which can be used to make resistance elements, thermocouple materials and compensation wires. Non-industrial white copper is mainly used to make decorative handicrafts.
Industrial white copper can be divided into structural white copper and precision resistance alloy white copper (electrical white copper).
Structural white copper is characterized by good mechanical properties, corrosion resistance and beautiful color. Among structural white copper, B30, B 10 and zinc white copper are most commonly used. In addition, there are aluminum white copper, iron white copper and niobium white copper. B30 has the strongest corrosion resistance among white copper, but it is more expensive. Aluminum white copper is close to B30 in performance and low in price, so it can be used as a substitute for B30. Zinc-white copper was produced and used in China in the15th century, and was called "China Silver". The so-called nickel silver or German silver also belongs to this kind of zinc white copper. Zinc can be dissolved in copper and nickel in large quantities, resulting in solid solution strengthening and corrosion resistance. Zinc-white copper can be successfully cut into various precision parts after adding lead, so it is widely used in instruments and medical devices. This alloy has high strength, corrosion resistance, good elasticity, beautiful appearance and low price. Aluminum in aluminum white copper can significantly improve the strength and corrosion resistance of the alloy, and its precipitates can also produce precipitation hardening.
Structural white copper is widely used in manufacturing precision machinery, chemical machinery and ship parts.
White copper (electric white copper) for precision resistance alloy has good thermoelectric properties. BMn 3- 12 manganese copper, BMn 40- 1.5 constantan, BMn 43-0.5 constantan and new constantan (also known as nickel-free manganese white copper, containing 10.8 ~ 12.5% manganese, 2.5 ~ 4.5) Manganese white copper is a kind of precision resistance alloy. This alloy has high resistivity and low temperature coefficient of resistivity, and is suitable for making standard resistance elements and precision resistance elements. It is a material for manufacturing precision electrical instruments, rheostats, meters, precision resistors and strain gauges. Kangtong and Kaotong have high thermoelectric potential and can also be used as thermocouples and compensation lines.