آندايزينگ تيتانيم در محلولهاي پايه سولفات

The surface of titanium exposed to atmosphere is coverd with thin layer of TiO2. This layer oxide due to low thickness, high porosity and low mechanical strenght can not protect its surface from corrosion. So, in order to produce oxide layers on the surface of titanum, anodizing is performed. In this research, anodizing of titanium was performed in H2SO4 and (NH4)2SO4 solutions at 25 ° C. Anodizing of titanium in H2SO4 solution was performed under galvanostatic conditions and in (NH4)2SO4 was performed under potentiostatic condintions. The results show that layers formed in H2SO4 are compact and then they are been porous and stable. These layers contain high relative porosity and the variations of thickness relative to time is logarithmic. Anodic layers formed in (NH4)2SO4 are compact and insulator. The thickness of layers increases with increasing of concerntration, but after decreasing of current and reaching to zero, increasing of time had no affected in thickness. The SEM and XRD techniques show that these layers are amorphous.