A CRITERION FOR THE PREDICTION OF SHEAR BAND ANGLES IN FCC METALS

The formation of shear bands has been followed in the rolling of an age-hardened Al-4% Cu aluminium alloy. while some grains were found to shear readily, some grains were not prone to localized shear. Current criteria of shear band angle prediction are ambiguous. Analysis in this paper shows that the most likely shear band propagation angle is the one which has the greatest texture softening among the ones with the same minimum number of slip systems and shear strength. Whether a shear band will form or not will then depend on the balance between the strain hardening rate of the slip planes and the texture softening factor. The prediction agrees well with the frequent occurrence of approximately 19-degrees and approximately 35-degrees shear bands found in the aluminum alloy and is successful in accounting for shear band angles in other systems.