Performance Comparison of Aluminum Alloy Cables and Aluminum Core Cables
1. Conductivity: Aluminum alloy is an emerging conductive material formed by adding elements such as iron and copper to pure aluminum through an alloying process. It's well known that the addition of various alloying elements to aluminum reduces its conductivity. However, through process control, the conductivity can be restored to a level close to that of pure aluminum, resulting in a similar current carrying capacity.
2. Creep Resistance: Pure aluminum has poor creep resistance. Thermal expansion and contraction caused by power on and off can cause significant creep at the joints. Over time, this can lead to loosening, increased contact resistance, and overheating, which can easily cause accidents. The creep resistance of aluminum alloy is approximately 300% that of pure aluminum, significantly reducing the possibility of loosening in cable joints and improving conductor connections.
3. Mechanical Properties:
3.1. Bending Properties: The national standard "Extruded Insulated Power Cables and Accessories for Rated Voltages 1 kV (Um = 1.2 kV) to 35 kV (Um = 40.5 kV)" (GB/T 12706-2008) stipulates that the minimum bending radius for aluminum-core cables during installation is 20 times the cable's outer diameter (single-core unarmored), 15 times the cable's outer diameter (single-core armored,
three-core unarmored), and 12 times the cable's outer diameter (three-core armored). The national standard "Aluminum Alloy Core Extruded Insulated Power Cables for Rated Voltages 1 kV (Um = 1.2 kV) to 35 kV (Um = 40.5 kV)" (GB/T 31840-2015) stipulates that the minimum bending radius for aluminum alloy cables with interlocking armor is 7 times the cable's outer diameter.
3.2. Flexibility: Aluminum alloy single wires undergo repeated bending performance tests in accordance with GB/T 4909.5. The minimum bending fracture frequency is greater than or equal to 25. Aluminum alloy cables that pass the repeated bending performance test can withstand dozens of bends, eliminating the potential for accidents during installation and use of previous aluminum core cables and significantly improving safety.
3.3. Tensile Strength and Elongation: Compared to pure aluminum conductors, aluminum alloy conductors, due to the addition of additional chemical components and the use of special processing techniques, maintain a tensile strength of 98 to 159 MPa while increasing elongation to over 10%, making them safer and more reliable to use.
