Formation of growing integrated layer [GIL] between ceramics and metallic materials for improved adhesion performance

In the ceramic/metal joining and coating, the most difficult problem is how to overcome poor adhesion of ceramic layers by their cracking and/or peeling arising from their intrinsic brittleness. On the basis of accumulated results and discussion, we propose a novel concept and technology of formation “Graded Intermediate Layer” or “Growing Integrated Layer” [GIL] between ceramics and metallic materials to improve the adhesion performance. Those GIL(s) can be prepared from a component of the metallic materials by chemical and/or electrochemical reactions in a solution at low temperatures of RT-200 °C. BaTiO3 or SrTiO3/TiOx GIL films on Ti plates formed by hydrothermal–electrochemical method showed good adhesion. CaTiO3/Al2O3/Ti2Al GIL films on TiAl exhibited excellent adhesion and anti-oxidation performances. The GIL strategy is effective for metallic alloys and bulk metallic glasses because they generally contain active component(s).