When doing home decoration, copper wires and aluminum wires should not be directly connected together. This is because there are some problems in the electrical connection between copper and aluminum. The specific reasons are as follows
Below
1. Electrochemical corrosion: Copper and aluminum can undergo electrochemical corrosion in the air. When they come into contact, especially in a humid environment, aluminum acts as the negative electrode
Corrosion occurs, and copper serves as the positive electrode, causing the joint part of the aluminum wire to gradually corrode and increase the contact resistance.
Second, difference in resistivity: The resistivity of copper is lower than that of aluminum, which means that copper wire has a smaller resistance and better electrical conductivity under the same conditions. When copper wire and aluminum wire are directly connected
When connecting, due to the different resistivity, the resistance at the connection point will increase.
Three, different coefficients of thermal expansion: Copper and aluminum have different coefficients of thermal expansion, which means that they expand to different degrees when the temperature changes, and this may lead to problems at the connection points
A gap is generated, thereby increasing the contact resistance.
