Über den Einbau von Phosphor in Aluminiumhydroxide und anodische Aluminium-Oxidschichten

The Incorporation of Phosphorus into Aluminium Hydroxides and Anodic Aluminium Oxide Films The in corporation of phosphorus during the anodic oxidation of high purity aluminium in phosphoric acid solutions increases with formation voltage (20 V to 100 V) and formation temperature. There is a minimum of phosphorus incorporation at a current density of 5 mA/cm². For this case, a dependence of porous oxide layer formation and an impurity ion incorporation with current density is discussed. Aluminium covered with a hydroxide film produced by a pretreatment with hot water before anodic oxidation exhibits phosphorus contents independent of formation voltage and current density but increasing with temperature. Hence, it follows, that no porous layer is formed and that phosphorus is incorporated predominantly by chemical reaction of hydroxide and phosphoric acid. The concentration of phosphorus is determined by using the radiotracer method.