Accession Number : ADA199842

Title :   Growth of Small Cracks in Aeroengine Disc Materials.

Descriptive Note : Final rept. Aug 85-Jan 88,

Corporate Author : SOUTHWEST RESEARCH INST SAN ANTONIO TX

Personal Author(s) : Hudak, S J , Jr ; Davidson, D L ; Chan, K S

PDF Url : ADA199842

Report Date : Jun 1988

Pagination or Media Count : 249

Abstract : Growth rate data for small fatigue cracks in fine grained and coarse grained Astroloy and in coarse grained Waspaloy were obtained at temperatures of 25 C, 200 C, and 600 C. Expressing the crack growth kinetics in terms of the linear elastic parameter resulted in small cracks growing faster than large cracks in all cases except that of the fine grained Astroloy at elevated temperature. This difference occurred even though the crystallographic nature of cracking in small cracks was shown to be the same as that in large cracks, based on metallographic, selected area electron channeling, and fractographic information. Furthermore, the fracture morphology of small and large cracks also exhibited the same dependence on temperature and applied stress level indicating that the crack propagation mechanism was the same in both cases. (jes)

Descriptors :   *CRACK PROPAGATION, CRACKS, ELASTIC PROPERTIES, FATIGUE(MECHANICS), FRACTOGRAPHY, FRACTURE(MECHANICS), GROWTH(GENERAL), HIGH TEMPERATURE, KINETICS, LINEARITY, MORPHOLOGY, PARAMETERS, RATES, STRESSES

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE