When purchasing industrial aluminum profiles, those that have undergone surface oxidation treatment are more expensive than the base material. However, unless you are an industry insider, it can be difficult to tell from the appearance alone whether the aluminum has been oxidized. In fact, identifying whether industrial aluminum profiles have undergone surface oxidation is quite simple. Here, the editor from Meicheng Aluminum introduces two methods for you. Method 1: Scratch the surface of the aluminum profile lightly with metal or a nail. If there are no scratches and the fingerprint left behind can be easily wiped off with a soft cloth, and the gloss remains unchanged after wiping, it is oxidized aluminum. Conversely, if there are scratches or the fingerprint is not easily wiped off, and there are small scratches on the surface or the scratches become more blurred after wiping, it is non-oxidized aluminum.
Method 2: Gently place the two probes of a multimeter on the surface of the aluminum material (do not press hard on the aluminum plate), turn the current to the maximum, and if the pointer on the multimeter moves, it indicates non-alumina; if the resistance is high and the pointer does not move, it indicates alumina.