Mechanical Properties, Including Fracture Toughness and Fatigue, and Resistance to Stress-Corrosion Cracking, of Stress-Relieved Stretched Aluminum Alloy Extrusions.

摘要

The tensile, compressive, shear, bearing, fracture-toughness and axial-stress fatigue properties and resistance to stress-corrosion cracking have been determined for a total of 143 lots of commercially produced 2014, 2024, 6061, 7075, 7079 and 7178 extrusions in stress-relieved stretched tempers (TX51X), and in thicknesses from 0.050 to 6.500 in. Tests of 34 lots in the 'heat-treated-by-user' tempers were also made. Ratios of tensile, compressive, shear and bearing properties to corresponding longitudinal tensile properties were computed. Some variations in ratios occur with respect to alloy, temper, thickness, and direction. Groups of ratios for each alloy in the TX51X tempers were analyzed statistically and minimum-average values were determined. Tables of design mechanical properties were prepared. Typical and minimum stress-strain and compressive tangent-modulus curves were prepared. Log-mean fatigue-life values were calculated. Stress-corrosion tests evaluated performance for the alloy and temper combinations tested. (Author)