Strain-controlled fatigue of a braze clad Al-Mn-Mg alloy at room temperature and at 75 and 180 degrees C

Strain-controlled fatigue test results at room temperature. 75 and 180 degr ees C for a braze clad Al1Mn0.5Mg (wt.%) alloy with the designation 3005LL are presented. The tests have been executed on flat specimens with a 10 mm gauge length. The total strain ranges vary from 0.4 to l.2%. The frequency is 0.5 Hz and the waveform triangular. The influence of the cladding on the fatigue properties is strain range dependent. The fatigue life for clad sp ecimens is shorter than that for the unclad core material at higher strain ranges while the life difference is small at lower strain ranges. The resul ts show that cracks during fatigue propagate through the brittle eutectic z ones in the cladding layer and into the core, thereby degrading the fatigue life. The test temperature influences the fatigue properties of 3005LL. Wh en the combination of stress and strain (half-life hysteresis energy) is co nsidered as the controlling parameter for the strain-controlled fatigue of 3005LL, however, the fatigue properties are similar at different test tempe ratures. (C) 1999 Elsevier Science S.A. All rights reserved.