We are all familiar with copper wire and aluminum wire, but I want to ask you whether these two wires can be connected together? Why? You may not know much.
Now let me popularize science.
Advantages and disadvantages of copper wire and aluminum wire:
In the same area, copper wire has greater load than aluminum wire, copper wire has better flexibility than aluminum wire, copper wire has lower resistivity than aluminum wire, and copper wire has better stability than aluminum wire.
However, copper wire is about 3.5 times the price of aluminum wire.
So many people choose to use aluminum wire in order to save money, but we strongly recommend copper wire.
This money can’t be saved!
If some friends first use aluminum wire and then buy copper wire. Can copper wire and aluminum be connected directly?
The answer is No.
Why can’t copper wire and aluminum wire be connected together?
Copper aluminum wire joint
The chemical and physical properties of copper and aluminum are very different and should not be directly connected.
However, copper aluminum connection is inevitable.
When connection is required, copper aluminum transition clamp, copper aluminum transition joint, copper wire tinned or aluminum wire tinned are generally used for direct connection.
Because the electrochemical properties of copper and aluminum are different.
If they are connected directly, once they encounter the electrolyte formed by water, carbon dioxide and other impurities, they form a chemical battery.
This is because aluminum is easy to lose electrons and become the negative electrode, while copper is difficult to lose electrons and become the positive electrode.
Therefore, a 1.69V electromotive force is formed between the positive and negative electrodes, and a small current passes through to corrode the aluminum wire, which is the so-called electrochemical corrosion.
This will cause poor contact between copper and aluminum and increase the contact resistance.
When a current passes through, the temperature of the joint will rise, which will accelerate the corrosion of the joint and increase the contact resistance, resulting in a vicious circle, until it is burned, and even cause a fire.