Surface treatment of stainless steel by electrolytic oxidation and deposition of titanium complexing ion solution to improve metal-ceramic adhesion

Abstract

Etched stainless steel plates were prepared using electrolytic oxidation while varying the applied voltage and reaction time. The morphology of the surfaces of the etched stainless steel plates was investigated using scanning electron microscopy. A hierarchical pore network with multiple pore sizes was observed on the etched surface. It is thought that these structures on the metal surface contributed to an improvement in metal-ceramic adhesion by linking with ceramic particles. Citratoperoxotitanate(IV) is a typical titanium complexing ion containing carboxyl groups. Therefore, this complex ion was expected to readily form organic-inorganic hybrid chemical bonds on the metal surface. Water-soluble citratoperoxotitanate(IV) was synthesized via a ‘peroxotitanate’ intermediate. The titanium complexing solution was mixed with a catalyst solution and the product was used to coat the stainless steel plates. The complexing ion formed chemical bonds, such as Fe-COO-Ti, on the steel surface. Improved adhesion was observed between the metal and ceramic particles, attributed to the organic-inorganic chemical bonds.