Fracture behavior of advanced ceramic hot-gas filters

Technical Report · Wed May 01 04:00:00 EDT 1996

DOI:https://doi.org/10.2172/237337· OSTI ID:237337

Singh, J P; Majumdar, S; Sutaria, M; Bielke, W

We have evaluated the microstructural/mechanical, and thermal shock/fatigue behavior and have conducted stress analyses of hot-gas candle filters made by various manufacturers. These filters include both monolithic and composite ceramics. Mechanical-property measurement of the composite filters included diametral compression testing with O-ring specimens and burst testing of short filter segments using rubber plug. In general, strength values obtained by burst testing were lower than those obtained by O-ring compression testing. During single-cycle thermal-shock tests, the composite filters showed little or no strength degradation when quenched from temperatures between 900 and 1000{degrees}C. At higher quenching temperatures, slow strength degradation was observed. The monolithic SiC filters showed no strength degradation when quenched from temperatures of up to {approx}700-900{degrees}C, but displayed decreased strength at a relatively sharp rate when quenched from higher temperatures. On the other hand, a recrystallized monolithic SiC filter showed higher initial strength and retained this strength to higher quenching temperatures than did regular SiC filters. This may be related to the difference in strength of grain boundary phases in the two cases. In thermal cycles between room temperature and 800- 1000{degrees}C, both monolithic and composite filters show a small strength degradation up to three cycles, beyond which the strength remained unchanged. Results of rubber-plug burst testing on composite filters were analyzed to determine the anisotropic elastic constants of the composite in the hoop direction. When these results are combined with axial elastic constants determined from axial tensile tests, the composite can be analyzed for stress due to mechanical (e. g., internal pressure) or thermal loading (thermal shock during pulse cleaning). The stresses can be compared with the strength of the composite to predict filter performance.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 237337
• Report Number(s): ANL/ET/CP--89702; CONF-9605167--1; ON: DE96011129
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
36 MATERIALS SCIENCE
CERAMICS
COMPOSITE MATERIALS
EXPERIMENTAL DATA
FILTERS
HOT GAS CLEANUP
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
SILICON CARBIDES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K