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In physical chemistry and engineering, passivation is coating a material so that it becomes "passive", that is, less readily affected or corroded by the environment. . Passivation involves creation of an outer layer of shield material that is applied as a microcoating, created by chemical reaction with the base material, or allowed to build by spontaneous oxidation
Chemical coloring of metals is the process of changing the color of metal surfaces with different chemical solutions. The chemical coloring of metals can be split into three types: electroplating – coating the metal surface with another metal using electrolysis. patination – chemically reacting the metal surface to form a colored oxide or salt.
Phosphate conversion coating is a chemical treatment applied to steel parts that creates a thin adhering layer of iron, zinc, or manganese phosphates, to achieve corrosion resistance, lubrication, or as a foundation for subsequent coatings or painting. [ 1][ 2][ 3] It is one of the most common types of conversion coating.
Aluminium oxide in its powdered form. Al 2 O 3 is an electrical insulator but has a relatively high thermal conductivity ( 30 Wm−1K−1) [ 2] for a ceramic material. Aluminium oxide is insoluble in water. In its most commonly occurring crystalline form, called corundum or α-aluminium oxide, its hardness makes it suitable for use as an ...
Decoupage or découpage ( / ˌdeɪkuːˈpɑːʒ /; [ 1] French: [dekupaʒ]) is the art of decorating an object by gluing colored paper cutouts onto it in combination with special paint effects, gold leaf, and other decorative elements. Commonly, an object like a small box or an item of furniture is covered by cutouts from magazines or from ...
Aluminothermic reactions are exothermic chemical reactions using aluminium as the reducing agent at high temperature. The process is industrially useful for production of alloys of iron. [ 1] The most prominent example is the thermite reaction between iron oxides and aluminium to produce iron itself: Fe 2 O 3 + 2 Al → 2 Fe + Al 2 O 3.
The Hall–Héroult process is the major industrial process for smelting aluminium. It involves dissolving aluminium oxide (alumina) (obtained most often from bauxite, aluminium 's chief ore, through the Bayer process) in molten cryolite and electrolyzing the molten salt bath, typically in a purpose-built cell. The Hall–Héroult process ...
Cobalt blue is a blue pigment made by sintering cobalt (II) oxide with aluminium (III) oxide (alumina) at 1200 °C. Chemically, cobalt blue pigment is cobalt (II) oxide-aluminium oxide, or cobalt (II) aluminate, CoAl 2 O 4. Cobalt blue is lighter and less intense than the (iron-cyanide based) pigment Prussian blue.