Y- and La- Containing Ln_3MO_7 (M= Nb or Ta) Pyrochlores as Corrosion - Resistant Coatings for High Temperature Combustion Applications

摘要

Ceramics based on mixed metal niobates and tantalates and possessing the pyrochlore and mixed structures (Ln_3MO_7, where Ln = rare earth, Y or Sc; M = Nb or Ta) were synthesized by using conventional ceramic methods. They show initial promise as protective coatings in corrosive environments at high temperatures. Thermal expansion properties for these materials were determined to be comparable to the austenitic steels used in high temperature systems which makes them highly promising as protective coatings for high temperature combustion applications.