What are the advantages of aluminum alloy cables compared to ordinary cables?
1. Electrical conductivity: The conductivity of aluminum alloy is 61.5% of that of copper IACS, the most commonly used reference material, and its current carrying capacity is 79% of that of copper, which is better than the standard of pure aluminum.
2. Creep resistance: The alloy material and annealing process of aluminum alloy conductors reduce the tendency of conductors to "creep" under heat and pressure. Compared with pure aluminum, the creep resistance is improved by 300%, avoiding relaxation problems caused by cold flow or creep.
3. Tensile strength and elongation: Compared with pure aluminum conductors, aluminum alloy conductors have significantly improved tensile strength and elongation up to 30% due to the addition of special components and special processing technology, making them safer and more reliable to use.
4. Coefficient of Thermal Expansion: The coefficient of thermal expansion is used to calculate the dimensional changes of a material as temperature changes. Aluminum alloys have a coefficient of thermal expansion comparable to copper. For many years, aluminum connectors have been reliably used with both copper and aluminum conductors, and most electrical connectors used today are made of aluminum, making aluminum alloys particularly suitable. Therefore, the expansion and contraction of the aluminum alloy conductor and the connector are completely synchronized.
5. Strong self-weight bearing capacity: Aluminum alloy improves the tensile strength of pure aluminum. Aluminum alloy cables can support the self-weight of 4000 meters, while copper cables can only support 2750 meters. This advantage is particularly prominent in the wiring of large-span buildings (such as stadiums).
6. Corrosion Resistance: Aluminum's inherent corrosion resistance stems from the thin, strong oxide layer that forms on its surface upon contact with air. This oxide layer is particularly resistant to various forms of corrosion. The addition of rare earth elements to the alloy further improves its corrosion resistance, especially against electrochemical corrosion. Aluminum's ability to withstand harsh environments makes it widely used as conductors in cable trays, as well as in many industrial components and containers. Corrosion typically occurs at the junctions of dissimilar metals in humid environments. Appropriate protective measures can be used to prevent corrosion, such as the use of lubricants, antioxidants, and protective coatings. Alkaline soils and certain types of acidic soils are highly corrosive to aluminum; therefore, directly buried aluminum conductors should use insulation layers or molded sheaths to prevent corrosion. In sulfur-containing environments, such as railway tunnels and similar locations, aluminum alloys exhibit significantly better corrosion resistance than copper.
7. Flexibility: Aluminum alloys possess excellent bending properties. Their unique alloy formula and processing technology significantly enhance their flexibility. Aluminum alloys are 30% more flexible than copper and have 40% less resilience. The bending radius of a typical copper cable is 10-20 times its outer diameter, while the bending radius of an aluminum alloy cable is only 7 times its outer diameter, making terminal connections easier.
8. Armor Characteristics: Most domestically used armored cables employ steel tape armor, which has a low safety level and poor resistance to external forces, making it prone to breakdown. They are also heavy, resulting in high installation costs, poor corrosion resistance, and a short service life. Our metal-interlocked armored cable, developed according to American standards, uses aluminum alloy tape interlocking armor. The interlocking structure between its layers ensures the cable can withstand strong external forces. Even under significant pressure and impact, the cable is less likely to break down, improving safety performance. Simultaneously, the armor structure isolates the cable from the external environment. Even in a fire, the armor layers improve the cable's flame retardant and fire-resistant rating, reducing the fire hazard. Compared to steel tape armor, the aluminum alloy tape armor structure is lighter, easier to lay, and can eliminate the need for cable trays, reducing installation costs by 20% to 40%. Different outer sheath layers can be selected depending on the application, making the armored cable more versatile.
9. Compaction Characteristics: While aluminum alloys are inferior to copper in terms of volumetric conductivity, our developed conductors not only improve material properties but also achieve significant breakthroughs in manufacturing processes. We employ unconventional compaction technology, achieving a compaction coefficient of 0.93, and for shaped wires, a coefficient of 0.95 – a first in China. This maximum compaction compensates for the lower volumetric conductivity of aluminum alloy cables, making the stranded conductor core behave like a solid conductor, significantly reducing the core's outer diameter and improving conductivity. Under the same current-carrying capacity, the conductor's outer diameter is only 10% larger than that of copper cables.
