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.
Aluminum is resistant to breakdown because it forms a strong chemical bond with oxygen. This is why aluminum often becomes discolored or dull in appearance. To clean aluminum, acid needs to be used in order to neutralize the buildup of oxidation.Follow these steps for using acid wash on aluminum products.luminum is resistant to breakdown because it forms a strong chemical bond with oxygen. This is why aluminum often becomes discolored or dull in appearance. To clean aluminum, acid needs to be used in order to neutralize the buildup of oxidation.