Fatigue and Anisotropic behaviours of cold rolled AA1200 Aluminium Alloy

This study examines the fatigue and anisotropy behaviour of cold rolled AA1200 aluminum alloy for light weight automotive connecting rod application. Aluminum (Al) 1200 ingots were melted at temperature of 680 °C (after one hour of heating) cast in sand mould and cast samples homogenized for 6 hrs at 480 °C. The cold rolling process was carried out after homogenisation for 10, 20, 30, 40 and 50% thickness reductions. The samples were characterised in 0°, 15°, 30°, 45°, 60°, 75° and 90° to the rolling direction. The results show that degree of deformation increase linearly with mean stress, stress range, stress ratio, stress amplitude, thickness and area ratio for all the reductions and directions examined. Area and thickness ratio increases linearly with deformation at higher inclination ( 150). The fatigue life obtained in this work shows life cycles at different degrees of deformation: 7.5 x 10^4 cycles at 10% reduction, 1.3 x10^5 cycles at 20% reduction, 4.3 x 10^4 cycles at 30% reduction; 2.6 x 10^5 cycles at 40% reduction and 1.09 x 105 cycles at 50% reduction). The results of this study provide evidence that systemic controlled cold deformation can potentially be used to significantly enhance the fatigue life of AA1200 aluminum alloy components subjected to cyclic loadings.