Time-dependent creep behavior of amorphous ZrCu and nanocrystalline Zr thin films - A comparison

Nanoindentation time-dependent relaxation tests were performed on the amorphous ZrCu, nanocrystalline Zr and multilayer ZrCu/Zr thin films aiming to explore the different time-dependent behaviors of these materials under the similar load level at room temperature. There appears an interesting crossing phenomenon of the creep rate as a function of applied stress. In comparison with the ZrCu thin films, the Zr film shows higher load/stress sensitivity for the creep response, suggesting the operating of dislocation creep along various slip systems and some minor grain-boundary-sliding creep mechanism. Multilayered ZrCu/Zr thin films also exhibit higher creep response due to the presence of numerous interfaces.