Advanced Ceramic Seal Program (Phase I).
Abstract
Screening of candidate ceramic seal materials was conducted to select the most promising systems for turbine seal component development. Vendor screening coupled with a literature search and preliminary thermal analysis identified five ceramic seal systems and one blade tip system for testing and evaluation in this contract. The ceramic seal materials were divided into two categories (1) insulative ceramic materials which could be applied to a metallic substrate and (2) structural ceramic materials to be mechanically held in place. Yittria stabilized zirconia was selected as the primary insulative ceramic material and reaction sintered silicon nitride was selected as the primary structural ceramic material to be used in these systems. Physical properties measurements of: coefficient of thermal expansion, thermal conductivity, and modulus of elasticity were performed on the selected seal materials. Thermal shock, oxidation/erosion and abradability were conducted on the seal and blade tip systems. Analysis of the test results and thermal and stress analysis under advanced engine conditions resulted in the selection of the best graded metal/ceramic system and the best structural system for turbine seal component development. Hot pressed silicon nitride and hot pressed silicon carbide were also analyzed for thermal and stress levels under advanced engine conditions. The recommended systems are: System 3 (yittria/calcia stabilized zirconia graded with a nickel chromium metallic constituent and brazed to a metallic substrate) and hot pressed silicon carbide. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1974
- Accession Number
- AD0781004
Entities
People
- P. W. Schlike
Organizations
- Pratt & Whitney