Ductility improvement and fatigue studies in Mg-CNT nanocomposites

The ductility improvement and fatigue behaviour of magnesium reinforced with 1.3 wt% of carbon nanotubes (CNTs) were investigated in this study. Dislocation studies were conducted to determine the deformation behaviour of the nanocomposite. A comparison was made between Mg-1.3CNT nanocomposite and monolithic Mg to identify the effect of CNTs on Mg. Ductility improvement was found to be the result of the high activity of the basal slip system and the initiation of prismatic 〈a〉 slip. Constant stress amplitude cyclic tests revealed that the cycles to failure for the Mg-1.3CNT nanocomposite is lower than that of the monolithic Mg. Both monolithic Mg and Mg-1.3CNT nanocomposite were found to harden upon cycling. The formation of sessile forest dislocations was identified as one of the main hardening causes.