NationMaster - Encyclopedia: Passivation layer

Passivation is the process of making a material "passive" in relation to another material prior to using the materials together. For example, prior to storing hydrogen peroxide in an aluminium container, the container can be passivated by rinsing it with a dilute solution of nitric acid and peroxide alternating with deionized water. The nitric acid and peroxide oxidizes and dissolves any impurities on the inner surface of the container, and the deionized water rinses away the acid and oxidized impurities. Hydrogen peroxide (H2O2) is a clear liquid, slightly more viscous than water, that has strong oxidizing properties and is therefore a powerful bleaching agent that has found use as a disinfectant, as an oxidizer, and (particularly in high concentrations as high test peroxide (HTP)) as a monopropellant in rockets. ... General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13, 3, p Appearance silvery Atomic mass 26. ... Flash point not applicable R/S statement R: ? S: ? RTECS number ? Supplementary data page Structure and properties n, Îµr, etc. ... Deionized water (DI water or de-ionized water; Commonwealth English deionised water) is water that lacks ions, such as cations from sodium, calcium, iron, copper and anions such as chloride and bromide. ... To oxidize an element or a compound is to increase its oxidation number. ...

In the context of corrosion, passivation is the spontaneous formation of a hard non-reactive surface film that inhibits further corrosion. This layer is usually an oxide or nitride that is a few atoms thick. Under normal conditions of pH and oxygen concentration, passivation is seen in such materials as aluminium, magnesium, copper, stainless steel, titanium, and silicon. Ordinary steel can form a passivating layer in alkali environments, as rebar does in concrete. The conditions necessary for passivation are recorded in Pourbaix diagrams. Some corrosion inhibitors help the formation of a passivation layer on the surface of the metals they come in contact with. Corrosion, atmospheric and biologic (Barnacles) Corrosion is deterioration of useful properties in a material due to reactions with its environment. ... The title of this article is shown beginning with a capital letter due to technical restrictions. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... Concentration is a very common concept used in chemistry and related fields. ... General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13, 3, p Appearance silvery Atomic mass 26. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11, 4, d Appearance metallic brown Atomic mass 63. ... In metallurgy, stainless steel (inox) is defined as a ferrous alloy with a minimum of 10. ... General Name, Symbol, Number titanium, Ti, 22 Chemical series transition metals Group, Period, Block 4, 4, d Appearance silvery metallic Atomic mass 47. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge Atomic mass 28. ... The old steel cable of a colliery winding tower Steel is a metal alloy whose major component is iron, with carbon being the primary alloying material. ... For the battery, see alkaline battery The word alkali can mean:- In chemistry, an alkali is a specific type of base, formed as a carbonate, hydroxide or other ionic salt of an alkali metal or alkali earth metal element. ... A tied rebar beam cage. ... Placing a concrete floor for a commercial building Installing rebar in a floor during a concrete pour In construction, concrete is a composite building material made from the combination of aggregate and cement binder. ... A Pourbaix diagram, also known as a potential/pH diagram, maps out possible stable (equilibrium) phases of an aqueous electrochemical system. ... Corrosion inhibitor - Wikipedia /**/ @import /w/skins-1. ...