Deposition From Non-Aqueous Solvents

A principal feature of metals if deposited cathodic from the hydrogen electrode is the co-development of hydrogen. This reaction reduces the current efficiency of the deposition process and can have a negative influence on the plated metal layer. The bubbles are responsible for defects in the film surface. Incorporation leads to poor mechanical properties. The hydrogen can penetrate into the plated parts. For example, if depositing zinc on steel it can reduce the mechanical properties of the steel parts. 

Another process is reduction of salts of the phosphorous acid. The phosphorous acid is reduced to phosphor, which is then incorporated into the metal in a larger amount. This can improve the properties. An example is nickel-phosphor with increased hardness. 

So far depKJsition from an aqueous electrolyte has been discussed. The number of metals that can be deposited from aqueous electrolytes is limited. Metal aluminum is used to demonstrate traditional and new ways of deposition from non-aqueous electrolytes. 

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