Thermally grown oxides (TGO) form at interfaces between the upper thermal insulation layers (TBCs) and the bond coats during operation. Macro cracks can be observed in many places in the TGO. The formation of macrocracks would reduce adhesion or lead to areas of stress peaks. To improve the adhesion, a modified powder for the boncoat was developed by adding cerium and silicon to the conventional MCrAlY. This paper investigates two kinds of TBC, which are a conventional CoNiCrAlY and a developed CoNiCrAlYCeSi bond coats. These TBCs are compared with regard to the oxidation behavior and the bond strength of the interface. To measure the adhesive strength, four-point bending tests are carried out with the normal TBC and the TBC with a modified bond coat. It is observed that the modified variant has a higher adhesive strength. The reason for this could be a reduction in the formation of mixed oxides. Paper includes a German-language abstract.