Why can't the copper and aluminum wires be connected together?

[China Aluminum Industry Network] mainly has the following three major reasons:

The chemical and physical properties of copper and aluminum are very different

So copper and aluminum should not be directly connected. Of course, the copper-aluminum connection is unavoidable. When a connection is required, a copper-aluminum transitional wire clip, a copper-aluminum transitional connector, a copper wire or a tin wire or a tin wire are directly connected.

The electrochemical properties of the two metals, copper and aluminum, are different

If they are directly connected, a chemical battery is formed when water, carbon dioxide, and other impurities form an electrolyte. This is because aluminum easily loses electrons and becomes a negative electrode. Copper is difficult to lose electrons and become a positive electrode. An electromotive force of 1.69 V is formed between them, and there is a very small current through which the aluminum wire is eroded, the so-called galvanic corrosion. This will cause poor contact between copper and aluminum, increasing contact resistance. When current is passed, the temperature of the joint will increase, and the temperature will increase and the corrosion of the joint will be accelerated, increasing the contact resistance and causing a vicious cycle until it burns.

Copper and aluminum are two different metals

Simply connecting them together will cause an electrochemical reaction (corrosion). The time is longer, the contact resistance at the connection increases and heats up, causing the circuit to turn off and on, the voltage fluctuating, and even causing a fire.