Accession Number : AD0289604

Title :   MATERIAL - 2024-T86 ALUMINUM - STRESS TREATED S-N FATIGUE CURVES FOR - DETERMINATION OF

Corporate Author : GENERAL DYNAMICS/FORT WORTH TEX

Personal Author(s) : BATTEIGER,J.C.

Report Date : 23 AUG 1955

Pagination or Media Count : 1

Abstract : Test results indicate that a slight increase in the fatigue life of 0.051-in. Al alloy sheet material stressed in tension-tension fatigue can be gained for stress levels below approximately 37,000 psi by applying a tensile stress of 35,000 psi to the material during the final 0.5 hour of the normal 375 F and 6.5 hour precipitation hardening treatment. The fatigue life at stress levels above approximately 37,000 psiAPPEARS TO BE REDUCED BY USING THIS TREATMENT TO REPLACE THE NORMAL PRECIPITATION HARDENING TREATMENT. Indications are that the endurance limit at 10,000,000 of tension-tension fatigue is increased from approximately 20,000 psi to approximately 23,000 psi by stressing the material in tension to 35,000 psi during the final 0.5 of the 6.5 hr 375 F precipitation hardening treatment. (Author)

Descriptors :   *ALUMINUM ALLOYS, DISPERSION HARDENING, FATIGUE (MECHANICS), STRESSES

Distribution Statement : APPROVED FOR PUBLIC RELEASE