DESIGN AND PROPERTIES OF THERMAL BARRIER COATINGS FOR ADVANCED TURBINE-ENGINES

The efficiency and performance of advanced aircraft turbines can be ma rkedly increased if higher gas temperatures are used. Although the hig hly loaded blades and vanes in the high pressure turbine are heavily c ooled, today's substrate materials are unable to provide sufficient st rength in the temperature range up to 1500 degrees C and above. If the rmal barrier coatings (TBCs) are applied on super-alloy turbine blades a substantial temperature drop of the parts can be achieved. The resu lting increase in efficiency comes from reduced cooling and/or increas ed gas turbine inlet temperatures of up to 150 degrees C. TBCs are eit her processed by plasma spraying (PS) or electron beam physical vapour deposition (EB-PVD). While PS is lower in cost EB-PVD leads to superi or strain and thermoshock tolerant coatings. Furthermore, cooling hole closure of turbine blades and vanes is prevented and aerodynamic desi gn maintained. Finally, future research and development needs in TBC t echnology are stressed.