Assessments of Mechanical and Life Limiting Properties of Two Candidate Silicon Nitrides for Stirling Convertor Heater Head Applications

摘要: NASA Glenn Research Center is developing advanced technology for Stirling convertors with a target of significantly improving the specific power and efficiency convertor overall generator Mars rovers deep space missions. One approach to has been recognized as use appropriate high-temperature materials. As series ceramic material approaches in Advanced Convertor Development Program fiscal year 2005, two commercial, structural silicon nitrides AS800 (Honeywell, Torrence, California) SN282 (Kyocera, Vancouver, Washington) were selected their mechanical life limiting properties characterized at 1050 C air. exhibited both strength Weibull modulus greater than SN282. A phenomenon was apparent low slow crack growth parameter n = 15; whereas, much increased resistance found 100. Difference elastic thermal conductivity negligible up 1200 between nitrides. The same true coefficient expansion 1400 C.