What factors are nonlinearly related to the current carrying capacity of Tube Type Contact Terminal?
Publish Time: 2024-11-11
The current carrying capacity of Tube Type Contact Terminal is one of its key performance indicators, and it has a complex nonlinear relationship with multiple factors.
Material properties
The conductivity of the material has a significant effect on the current carrying capacity, but it is not a simple linear relationship. For example, in some alloy materials, trace impurities or changes in the proportion of different elements may cause the conductivity to change in a complex way. When the crystal structure of the material changes due to temperature or processing technology, the electron mobility will also change, thus affecting the current carrying capacity. In addition, the hardness and strength of the material are also related to the current carrying capacity. When a harder material is subjected to the thermal stress generated by the current, it may generate internal stress due to different thermal expansion coefficients. If this stress exceeds a certain limit, it will cause the microstructure of the material to change, and then have a nonlinear effect on the current carrying capacity. For example, under high temperature and high current conditions, this effect is more obvious.
Contact pressure
The contact pressure and current carrying capacity are not monotonically increasing linearly. Appropriate contact pressure can reduce the contact resistance and thus improve the current carrying capacity. However, when the contact pressure exceeds a certain value, the elastic deformation of the contact terminal may be too large, changing its microscopic contact state, slowing down the rate of increase of the contact area or even causing local stress concentration, resulting in an increase in contact resistance and a decrease in current carrying capacity. In addition, long-term high pressure may cause wear and material fatigue on the contact surface, and these changes will also affect the current carrying capacity nonlinearly.
Temperature
The effect of temperature on the current carrying capacity of Tube Type Contact Terminal is complex and nonlinear. Generally speaking, an increase in temperature will increase the resistance of the material and reduce the current carrying capacity. However, in some special materials or specific temperature ranges, there may be some physical phenomena, such as changes in material properties near the superconducting critical temperature, or phase changes in the material at different temperatures, which will cause a sharp change in the current carrying capacity. Moreover, the increase in temperature will also affect the heat exchange between the contact terminal and the surrounding environment, further affecting its internal temperature distribution, and indirectly having a nonlinear effect on the current carrying capacity.
Surface condition
The surface roughness, oxide layer and other surface conditions of the contact terminal have a nonlinear relationship with the current carrying capacity. The smoother the surface roughness is, the higher the current carrying capacity is. Appropriate micro-roughness may be beneficial to increase the actual contact area, but if the roughness is too large, the contact resistance will increase. The existence of the oxide layer may play a protective role to a certain extent, but as the thickness of the oxide layer increases or in special environments such as high temperature and high humidity, the conductivity of the oxide layer changes, which will have a complex nonlinear effect on the current carrying capacity. For example, the oxide layer may hinder the passage of current under certain conditions, reducing the current carrying capacity.
