Structural Performance of Cylindrical Pressure Housings of Different CeramicCompositions Under External Pressure Loading. Part 3. Sintered Reaction Bonded Silicon Nitride Ceramic

摘要

Ten 12-inch-OD by 18-inch-long reaction-bonded sintered silicon-nitride cylinderswere fabricated, assembled, and pressure tested to determine their suitability for use as external pressure-resistant housings for underwater applications. The material, designated PSX Si3N4, is made by CERCOM, Inc. (Vista, CA) by a proprietary process. The primary advantages of this material are high compressive strength, high elastic modulus, high fracture toughness, and low specific gravity. Pressure test results are presented along with strain gage data and cyclic fatigue life data. Conclusions regarding the suitability of the material for application to pressure housings for underwater applications are presented along with a comparison to WESGO's AL-600 96-percent alumina ceramic, which was chosen as the base of comparison for various advanced materials being evaluated under the same program. Recommendations for design implementation, nondestructive inspection, and further research are made. Ceramics, External pressure housing, Ocean engineering.