THE CYCLIC FATIGUE, DAMAGE INITIATION, DAMAGE PROPAGATION and FINAL FRACTURE BEHAVIOR of ALUMINUM ALLOY 2524

摘要

In this paper is presented and discussed the results of a study aimed at evaluating the high cycle fatigue properties and final fracture behavior of aluminum alloy 2524. Specimens of the alloy, in the T351 temper, were cyclically deformed over a range of stress amplitudes at ambient temperature and at a stress ratio of 0.1. An increase in stress amplitude was found to have a detrimental influence on cyclic fatigue life of test specimens taken from both the longitudinal and transverse orientations of the wrought plate. At equivalent values of maximum stress the fatigue life of the test specimen in the longitudinal orientation was an order of magnitude greater than the fatigue life of the specimen taken from the transverse orientation. At a given stress amplitude, the macroscopic fracture mode was observed to be identical regardless of the orientation of the test specimen with respect to the wrought rolled plate. The mechanisms governing high cycle fatigue life and final fracture behavior of the alloy are discussed in light of the mutually interactive influences of microstructural effects, matrix deformation characteristics and maximum stress.