Notched-Fatigue Behavior to 7075-Base Aluminum Alloys.
Abstract
Ten different alloys based on the 7075 composition were utilized to study the effects of purity level (w/o Fe+Si) and dispersoid type on the notched fatigue behavior in two different environments. These same alloys were used in other AFML investigations to determine how the various precipitates found in commercial 7000 series aluminum alloys control the mechanical properties. Purity significantly affects the notched (Kt=3) fatigue life only in an inert test environment at the lowest load tested. Purity did not significantly affect the notched fatigue life when tests were conducted in an aggressive test environment. While the dispersoid type did change the macroscopic fracture appearance of the test specimen, this produced a small change in the notched fatigue life which was not significant at the one percent alpha level. By far, the test environment was more important than the metallurgical variables considered. This is somewhat surprising since the duraction of the tests were at most two days, allowing little time for corrosion. It appears that specifying stricter alloy purity levels or different dispersoid types will not improve the notched fatigue life of wrought 7000 series aluminum alloys. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1978
- Accession Number
- ADA053783
Entities
People
- Joseph F. Santner
- Joseph S. Santner
Organizations
- Air Force Research Laboratory