A Fundamental Study of Fatigue in Powder Metallurgy Aluminum Alloys.
Abstract
Processing-microstructure-fatigue relationships have been examined in high-strength powder metallurgy aluminum alloys (Al-Cu, Mg, Zn, Co) in air and salt fog. Three phases were included: (i) The combined effects of cobalt level and processing mode on fatigue life and resistance to crack propagation; (ii) The role of plane-strain forging on fatigue life and crack propagation response; (iii) The combined effects of cobalt level and processing mode on strain-controlled low-cycle fatigue. While the interplay between processing history, alloy composition and orientation is complex, a basic understanding of the role of microstructure on the crack initiation and propagation stages of fatigue has been obtained. Direct comparisons of the corresponding fatigue response of counterpart ingot metallurgy alloys were included. In general, the P/M processed material exhibits superior resistance to fatigue crack initiation compared to the I/M form. However the relative crack growth rates in the P/M and to the I/M form. However the relative crack growth rates in the P/M and I/M materials depend on orientation and the level of delta K. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1981
- Accession Number
- ADA105080
Entities
People
- Alan Lawłey
- M. J. Koczak
Organizations
- Drexel University