ANODIZING TITANIUM FOR SPACE APPLICATIONS

The work reported in this paper concerns a study on the anodizing of titanium in dilute sulphuric acid electrolyte at constant voltages. The effects of various parameters, e.g. bath composition, temperature, voltage and anodizing time, on the anodic film formation have been investigated to evaluate the optimum anodizing conditions. The anodic current density was found to increase with increasing applied voltage and with electrolyte temperature. The optical properties, i.e. solar absorptance alpha(s) and IR emittance epsilon(IR) of the anodic coatings obtained under different operating conditions have been evaluated. The effects of relative humidity, high temperature heating, thermovacuum performance and thermal cycling tests on the physical and optical properties of anodic coatings have been examined.