When selecting a terminal material, the following characteristics should be considered:
① Mechanical properties of materials. Strength, ductility, yield strength, hardness, etc.
②Electrical conductivity and thermal conductivity of the material. The electrical conductivity is directly proportional to the thermal conductivity, the thermal conductivity is related to the electrical conductivity of the terminal and its own resistance, and the thermal conductivity is related to the heat dissipation performance of the terminal.
③Resistance to stress relaxation. The terminal is divided into a crimping part and a connecting part. Elastic-plastic deformation of the crimped portion causes stress between the terminal and the wire. If stress relaxation occurs, the contact between the terminal and the wire becomes unstable. If the connecting parts of the terminals are connected by insertion deformation, stress relaxation and fatigue shall be considered.
④ material price. At present, enterprises attach great importance to the cost of raw materials, which is also a consideration.
Generally speaking, brass, phosphor bronze, beryllium bronze and other copper alloys are commonly used for terminals, and there are also high-conductivity copper alloys such as K88. Although copper is more conductive than silver, it has slightly poorer mechanical properties. Therefore, alloying elements with the same high electrical conductivity must be added to improve mechanical strength and heat resistance. Therefore, we can conclude that copper alloy is the best choice for connector material because of its luster, corrosion resistance and good processability.
Different copper alloys have different material properties, so the material of the terminal should be selected according to the purpose and requirements of the terminal.