Accession Number : AD0778212

Title :   Metallurgical Aspects of Fatigue and Fracture Toughness.


Report Date : DEC 1973

Pagination or Media Count : 95

Abstract : Stress corrosion has in a way been regarded largely as a disease of the alloy, while fatigue has become a design consideration. The latter applies also to fracture toughness, the capacity of the alloy to resist failure in the presence of a crack. Chemical compositions have been altered and heat treatments invented to raise the resistance to SCC, although special design measures - e.g. the avoidance of tensile stresses in the short transverse direction of the anisotropic microstructure - can also be very effective. In AGARD the need was recognized to inspect whether the fatigue and fracture behaviour of the aerospace structural alloys was affected to an important extent by changes in their microstructure. If so this could be exploited to improve the alloys by special processes e.g. thermomechanical treatments. Specialists were invited to inform the Structures and Materials Panel on this topic through pilot lectures. The information presented proved to highly valuable, not only for the purpose of the Panel but for everybody interested in aerospace structural materials.

Descriptors :   *Fatigue(Mechanics), *Fracture(Mechanics), *Microstructure, Thermomechanics, Metals, Aircraft, Crack propagation, Toughness, Stress corrosion, Aluminum alloys, Steel

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE