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Accession Number:
AD0919326
Title:
A Study of Properties and Behavior of High Temperature Gas Turbine Materials.
Corporate Author:
STANFORD RESEARCH INST MENLO PARK CA
Report Date:
1974-03-01
Abstract:
Expanded-ring tests were performed in 30 to 35 relative humidity air at 70 or - 2 F on specimens machined from two tiles of Norton HS-130 hot-pressed silicon nitride. No statistically significant variation of mean fracture strength could be detected for groups of specimens tested at stress rates between 150 psisec and 500,000 psisec. The mean fracture strength was also found to be independent of original specimen location in the tile. A significant difference in the mean fracture strengths of the two tiles was detected and was attributed to differences in the extreme-value volume distributions of flaw sizes. The fracture strength data for specimens from both tiles showed an excellent fit with single-valued two-parameter Weibull distributions. Values of the Weibull modulus for the two tiles were 9.67 and 11.01. The range of flaw sizes required to account for the fracture strength data was estimated from linear elastic fracture mechanics theory, and the existence of flaws with sizes within the estimated range was confirmed by scanning-electron fractography. Author
Descriptive Note:
Final rept. 31 May 73-31 Mar 74,
Pages:
0056
Contract Number:
DAAG46-73-C-0206
File Size:
0.00MB
