What are the advantages of aluminum alloy cables over ordinary cables?

1. Conductivity: the conductivity of aluminum alloy is 61.5% of the most commonly used reference material copper IACS, and the current carrying capacity is 79% of copper, superior to the pure aluminum standard.

2. Creep resistance: The alloy material and annealing process of aluminum alloy conductor reduce the “creep” tendency of the conductor under heat and pressure. Compared with pure aluminum, the creep resistance can be increased by 300%, avoiding the relaxation problem caused by cold flow or creep.

3. Tensile strength and elongation: compared with pure aluminum conductor, aluminum alloy conductor has been greatly improved in tensile strength due to the addition of special components and the use of special processing technology, and the elongation has been increased to 30%, making it safer and more reliable to use.

4. Coefficient of thermal expansion: the coefficient of thermal expansion is used to calculate the size change of materials when the temperature changes. The thermal expansion coefficient of aluminum alloy is equivalent to that of copper. For many years, aluminum connectors have been reliably used for copper and aluminum conductors, and most electrical connectors used today are made of aluminum, which is particularly suitable for aluminum alloys. Therefore, the expansion and contraction of aluminum alloy conductor and connector are completely consistent.

5. The aluminum alloy with strong deadweight bearing capacity improves the tensile strength of pure aluminum. The aluminum alloy cable can support the deadweight of 4000 meters, while the copper cable can only support 2750 meters. This advantage is particularly prominent in the wiring of long-span buildings (such as stadiums).

6. Corrosion resistance The inherent corrosion resistance of aluminum is due to the formation of a thin and solid oxide layer when the aluminum surface contacts with the air, which is particularly resistant to various forms of corrosion. The addition of rare earth elements in the alloy can further improve the corrosion resistance of aluminum alloy, especially electrochemical corrosion. Aluminum is widely used as conductor of cable in tray and many industrial components and containers due to its ability to withstand harsh environment. Corrosion is usually related to the connection of different metals in a humid environment. Corresponding protective measures can be used to prevent corrosion, such as lubricating oil, antioxidant and protective coating. Alkaline soil and some types of acid soil environment are highly corrosive to aluminum, so insulation layer or molded sheath shall be used for aluminum conductor directly buried to prevent corrosion. In sulfur containing environments, such as railway tunnels and other similar places, the corrosion resistance of aluminum alloys is much better than that of copper.

7. Flexible aluminum alloy has good bending performance. Its unique alloy formula and processing technology greatly improve the flexibility. Aluminum alloy is 30% more flexible than copper and 40% less resilient than copper. Generally, the bending radius of copper cable is 10-20 times the outer diameter, while the bending radius of aluminum alloy cable is only 7 times the outer diameter, which makes it easier to connect terminals.

8. Armouring characteristics: most of the armored cables commonly used in China are armored with steel tape, with low safety level. When they are damaged by external forces, they have poor resistance, which is easy to lead to breakdown. They are heavy and have high installation costs. In addition, they have poor corrosion resistance, so their service life is not long. The metal interlocking armored cable developed according to the American standard adopts aluminum alloy strip interlocking armor. The interlocking structure between layers ensures that the cable can withstand strong external destructive force. Even if the cable is subjected to greater pressure and impact force, the cable is not easy to be broken down, which improves the safety performance. At the same time, the armored structure insulates the cable from the outside world. Even in case of fire, the armored layer improves the flame retardant and fire-resistant level of the cable and reduces the risk factor of fire. Compared with steel strip armouring, aluminum alloy strip armouring structure is light in weight, convenient in laying, free of cable tray installation, and can reduce the installation cost by 20%~40%. Different outer sheath layers can be selected according to different places of use, which makes the use of armored cables more extensive.

9. The compaction characteristics are only considered from the aspect of volume conductivity. Aluminum alloy is inferior to copper. However, the conductor developed by the new technology has not only made improvement in material properties, but also made a great breakthrough in technology. The unconventional compaction technology is used to make the compaction coefficient reach 0.93, while the compaction coefficient of profiled wire can reach 0.95. The maximum limit compaction can make up for the shortage of aluminum alloy cable in volume conductivity, so that the stranded conductor core is like a solid conductor, which significantly reduces the outer diameter of the core and improves the conductivity. Under the same current carrying capacity, the outer diameter of the conductor is only 10% larger than that of the copper cable.