The contacts, the core of current switching, are constructed from a silver-based composite material. In addition to the basic silver-copper alloy, a small amount of nickel or tungsten particles are incorporated to form a dispersion-reinforced structure for high-frequency switching applications. Nickel
enhances resistance to welding, while tungsten improves wear resistance, making them particularly suitable for arc erosion under inductive loads. While maintaining silver's excellent conductivity, they extend contact life by approximately 30% and reduce contact failure caused by material transfer.
The coil assembly's conductors are primarily high-strength enameled copper wire. The enameling layer is made of modified polyester or polyimide, with a temperature rating exceeding 130°C to accommodate operating temperature rises. Select precision models incorporate a fiberglass cloth pad between the coil bobbin and the conductors to further enhance insulation strength and reduce the risk of short circuits caused by enameling aging.
The magnetic circuit structure's yoke and armature are constructed from low-carbon electrical steel (such as the DT4E series). Annealing reduces iron loss and ensures efficient magnetic field conversion. Compared to ordinary soft iron, its magnetic permeability is increased by approximately 20%, reducing coil excitation current and making the relay more sensitive, especially in low-voltage starting scenarios.
The housing is made of flame-retardant reinforced nylon (such as PA66+GF20). The addition of glass fiber enhances mechanical strength and impact resistance compared to ordinary plastics. It also meets the UL94 V-0 flame retardancy rating and can withstand external sparks and high temperatures.
