Thermal Shock Resistant Protective Silicide Coatings for High Temperature Applications.

Chemical and mechanical compatibility between the components of a composite determines its resistivity and applicability. It is shown that by modifying the composition of the components, it is possible to produce an applicable material. In the case of niobium and tantalum alloys protected by MoSi//2 coatings, it is not only possible to significantly improve thermal shock resistance for the range from 1000 to 1200 degree C by producing crystallized SiO//2-GeO//2 protective glassy coatings due to melting of GeO//2, but the feared vulnerability of MoSi//2 in the temperature range from 600 to 800 degree C could be completely eliminated. In this way, an outstanding refractory material has been developed which could be tested as a turbine blade-protective coating material at 100,000 g and 1100 degree C without destruction.