Editing Anodizing (section)

==History==
Anodizing was first used on an industrial scale in 1923 to protect [[Duralumin]] [[seaplane]] parts from corrosion. This early [[chromic acid]]–based process was called the Bengough–Stuart process and was documented in British [[specification (technical standard)|defence specification]] DEF STAN 03-24/3. It is still used today despite its legacy requirements for a complicated voltage cycle now known to be unnecessary. Variations of this process soon evolved, and the first sulfuric acid anodizing process was patented by Gower and O'Brien in 1927. Sulfuric acid soon became and remains the most common anodizing electrolyte.<ref name="sheasby ch7" />

Oxalic acid anodizing was first patented in Japan in 1923 and later widely used in Germany, particularly for architectural applications. Anodized aluminium extrusion was a popular architectural material in the 1960s and 1970s, but has since been displaced by cheaper [[plastic]]s and [[powder coating]].<ref name="sheasby ch8">{{harvnb|Sheasby|Pinner|2001| pp=597–742}}.</ref> The phosphoric acid processes are the most recent major development, so far only used as pretreatments for adhesives or organic paints.<ref name="sheasby ch7">{{harvnb|Sheasby|Pinner|2001|pp=427–596}}.</ref> A wide variety of proprietary and increasingly complex variations of all these anodizing processes continue to be developed by industry, so the growing trend in military and industrial standards is to classify by coating properties rather than by process chemistry.