Abrasive tip/abradable shroud system and method for gas turbine compressor clearance control

摘要

For use in a compressor unit of gas turbine engine, a blade having a tip portion. An abrasive portion is formed on the tip portion with the abrasive portion comprising a dispersion of discrete particles of cubic boron nitride disposed on the tip portion. A shroud is coated with a porous ceramic abradable material based on preferably 8% yttria-stabilized zirconia. The abrasive portion of the tip portion contacts the abradable material. In the preferred embodiment, the abradable material is treated with boron nitride composited polyester that is burned out of the material via thermal exposure to thereby improve porosity within the abradable material.