The dramatic Portevin-Le Chatelier effect in AlN/AZ91 composites induced by pyramidal <c plus a> dislocations shearing extension twins

The dramatic characteristics of serrated flow, i.e., Portevin-Le Ch & acirc;telier (PLC) effect was observed in AlN/AZ91 composites under uniaxial compression testing at 350 degrees C with a strain rate of 0.05 s(-1). The results show that the PLC effect mainly originates from the repeated shearing of extension twins by pyramidal dislocations in favorably orientated grains, while the profuse activation of extension twins and pyramidal dislocations was induced by AlN particles, which provides new insights into the PLC effect in magnesium-based materials.

Automated summary

The serrated flow, or Portevin-Le Châteleier (PLC) effect, was observed in AlN/AZ91 composites during uniaxial compression testing at 350 degrees C and a strain rate of 0.05 s(-1). The PLC effect was found to originate from the repeated shearing of extension twins by pyramidal dislocations in favorably orientated grains, while the presence of AlN particles induced profuse activation of extension twins and pyramidal dislocations, providing new insights into the PLC effect in magnesium-based materials.