What do aluminum busbars use to prevent oxidization at the joints?

Aluminum busbars often use silver or tin plating to prevent oxidation at the joints. When aluminum is exposed to air, it forms a thin layer of aluminum oxide that can inhibit electrical conductivity and lead to potential performance issues. By applying silver or tin plating at the joints, the surfaces are protected from oxidation, ensuring better conductivity and reliability in electrical applications.

The other options would not provide the same level of protection against oxidation. Copper strips may not be suitable due to the potential for galvanic corrosion when paired with aluminum. Heat-resistant paint could provide some degree of protection, but it would not be as effective in maintaining electrical conductivity as plating. Plastic sleeves do not facilitate electrical connection and would not address oxidation at all.