Hard Anodizing is an electrolytic passivation process one step used to increase the thickness of the natural oxide layer on the surface of aluminum parts.
Type III anodizing, hard anodizing one step is performed in a sulfuric acid bath containing 180-200 grams per Liter of acid and a small amount of dissolved aluminum. The operating temperature is controlled between 28-32º F
The power supply is a DC rectifier. Current densities can range from 24-40 amps per square foot (ASF),
The aluminum part being anodized is made the anode (or positive pole) in the system. The most efficient cathodes (or negative pole) are 6063t6 aluminum.
Current is applied to the system for a prescribed time, without preliminary steps, at
the desired current density to achieve the oxide thickness required (oxide thicknesses can range from 0.7 mil to 3.0 mils). The resulting porous oxide can then be colored or sealed but limitations on final color will determined by the
Two steps rinses follow the one step anodizing