Development of Abrasive Blade Tip Coatings for Use in an Abradable Turbine Gas Path Seal System.
Final rept. 1 Jan-31 Dec 76,
PRATT AND WHITNEY AIRCRAFT GROUP WEST PALM BEACH FL GOVERNMENT PRODUCTS DIV
Pagination or Media Count:
An abrasive blade tip treatment coating was developed which exhibited promising rub resistance against ceramic graded ZrO2-Ni Cr outer air seals. This bladeseal system was designed for advanced high pressure turbine sealing applications. The best tip treatment was produced by vacuum hot pressing a compact comprised of 50 volume percent of coated 8-mil diameter silicon carbide SiC grits in a MERL 711 CoNiCrAlY alloy matrix. The SiC grits were radio frequency RF sputter coated with a 0.1-mil thick aluminum oxide diffusion barrier coating prior to insertion in the matrix. This compact was transient liquid phase bonded to prepared rig and engine blade tips. The abrasive blade tip withstood fabrication, bonding, and heat treatment cycles with little or no grit dissolution and degradation. Bladeseal dynamic rub tests produced little blade tip wear compared with seal wear with no dynamic rub impact problems or any loss of abrasive blade tip treatment structural integrity. Author
- Coatings, Colorants and Finishes
- Jet and Gas Turbine Engines