Por que os fios de cobre e alumínio não podem ser conectados juntos?

Portanto, cobre e alumínio não devem ser conectados diretamente. Se a conexão cobre-alumínio for inevitável, copper-aluminum transition clips or copper-aluminum transition joints are required.

If they are directly connected, uma vez que encontram o eletrólito formado pela água, dióxido de carbono e outras impurezas, uma bateria química será formada. This is because aluminum is easy to lose electrons to become a negative electrode, and copper is difficult to lose electrons to become a positive electrode. An electromotive force of 1.69V is formed between, and a small current passes through, which corrodes the aluminum wire, which is the so-called galvanic 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 increase, which will further accelerate the corrosion of the joint, increase the contact resistance, and cause a vicious circle until it burns out.