a1 Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China
The mechanical response to indentation (including nano- and microindentation) has been investigated in Cu/Au and Cu/Cr multilayers with respective layer thickness ratios of 1:1 and 2:1, and individual layer thickness ranging from nanometer to submicrometer scale. It was found that the Cu/Cr multilayer has higher strength than the Cu/Au multilayer, although both multilayers have close Hall–Petch slope. Examination of indentation-induced deformation behavior shows that the Cu/Cr multilayer exhibits higher resistance to plastic deformation instability than the Cu/Au multilayer. Theoretical analysis indicates that the significant difference in mechanical response originates from the constituent layer configuration and interface structures, which impose distinguishing confining effect on dislocation activity.
(Received July 17 2008)
(Accepted September 19 2008)