This painless condition occurs when the little bumps on your tongue grow long and trap bacteria that live in your mouth -- making the tongue look black and hairy. Causes can include antibiotic use, poor oral hygiene, smoking, drinking a lot of tea or coffee, and not producing enough saliva.
Hello, Jie. The word passivate is a bit troublesome because aluminum cannot be passivated in the same sense as stainless steel; but it can be passivated in the same sense as zinc plating, i.e., with a chromate conversion coating.
Zinc Passivation. Like many metals, the good corrosion properties. of zinc are due to a thin film of corrosion. product that forms on the surface of the metal. This tightly-adherent corrosion film is called a. passivation layer. The formation of the. passivation layer is essential to achieving long-. life with a galvanized product.