Donald Joseph Baldwin

Development of Higher Temperature Abradable Seals for Gas Turbine Applications

Improving sealing between rotating and stationary parts in industrial turbines can significantly increase unit performance. Abradable seals are being developed to reduce blade-tip clearances where an abradable material is placed on the stationary shroud or casing opposite the rotating blade tips to reduce clearances with minimum risk to the turbine components during rubs. A newly developed metallic abradable material is a thermally sprayed coating on the first stage of gas turbine shrouds to reduce tip clearances; thereby, improving turbine power and efficiency by about 1/2 percent. This material is an improvement over currently available metallic abradables increasing the maximum operating temperature from 750°C to about 950°C with no special treatments required on the rotating blade tips. Initial engine field tests have shown the new material to be abradable and on target to meet life requirements.Copyright