Effect of Annealing on Mechanical Properties and Nanoscale Lamellar Structure in Co-Cu Alloy

Abstract

An electrodeposited Co-Cu alloy with a nanoscale lamellar structure was annealed at 673–973 K. The effects of annealing on the mechanical properties and the microstructures of the alloy such as the lamellar area ratio and the lamellar spacing were investigated. The Young’s modulus of the Co-Cu alloy increased by annealing. This is mainly due to a decrease in the lamellar area ratio. The as-deposited specimens exhibited a low value of the activation volume for plastic deformation; however, the activation volume was increased by annealing. This appears to be related to an increase in lamellar spacing caused by annealing. The origins of the lamellar spacing dependence of the activation volume are discussed from the viewpoint of the emission of dislocations from the lamellar boundary.