An investigation on instantaneous strain hardening behaviour in three dimensions of aluminium-iron composites during cold upsetting

Strain hardening of a material is an important phenomenon, which is required to study the plastic deformation of any material and also is an important parameter in the study of workability criteria of metals. The present investigation has been undertaken to evaluate the instantaneous strain hardening behaviour experienced during the cold working of sintered aluminium iron composites with various iron contents from 0 to 10% under various stress state conditions namely uniaxial, plane and triaxial. Sintered preforms with two different aspect ratios namely 0.44 and 0.75 with for different per cent of iron contents ranging from 0 to 10% were prepared and cold forged. The instantaneous strain hardening exponent (ni) and the instantaneous strength coefficient (Ki) were obtained for each aspect ratios and iron contents and found that they have showed tremendous variations in the instantaneous values of strain hardening exponent and strength coefficient for the addition of different iron content, for different aspect ratios and for different stress state conditions.