Accession Number : AD0770350

Title :   Program to Improve the Fracture Toughness and Fatigue Resistance of Aluminum Sheet and Plate for Aircraft Applications.

Descriptive Note : Final rept. Dec 71-Jul 73,


Personal Author(s) : Thompson,David S. ; Levy,Sander A. ; Spangler,Grant E. ; Benson,David K.

Report Date : SEP 1973

Pagination or Media Count : 116

Abstract : A variety of thermomechanical processing practices have been investigated in 2000 and 7000 series alloys. These have been of the form: solution heat treat, quench, preage, work harden and final age. In Task I the effects of Cu (1.9 and 1.3%) and Mg (2.5 and 1.7%) content of 7000 series alloys were evaluated together with the preage and thermomechanical working conditions. It was found that the highest properties were obtained with the lower Cu and Mg contents, with an overaged preage followed by a warm rolling operation. These findings were incorporated in Task II in the choice of alloy (RX725: 6% Zn, 2.4% Mg, 1.5% Cu, and .12% Zr) and by concentrating an overaged, warm rolled processing conditions. It was found that the goals of the contract would be achieved; however, some unexplained low toughness values were obtained. (Modified author abstract)

Descriptors :   *Aluminum alloys, *Fracture(Mechanics), Fatigue(Mechanics), Heat treatment, Mechanical working, Toughness, Yield strength, Rolling(Metallurgy), Crack propagation, Copper alloys, Magnesium alloys, Zinc alloys, Zirconium, Stresses, Elongation, Exfoliation, Tensile properties, Compressive properties

Subject Categories : Aircraft
      Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE