We examined the high temperature indentation response of physical vapor deposited Cu–TiN multilayered nanocomposites with layer thicknesses ranging from 5 nm to 200 nm. A decrease in hardness with increasing temperature was observed, along with a strong correlation between the hardness and the nanometer-level TiN grain sizes, rather than layer thickness. The apparent activation energies calculated from the high temperature indentation experiments indicated that, for all but the smallest layer thicknesses, the deformation of copper in the nanolaminates dominate the plastic response in these composites. In the finest layer thicknesses, a decrease in the apparent activation energy value indicated possible co-deformation of Cu and TiN.
Bibliographical noteFunding Information:
The authors would like to thank D. Frey & G. Buerki for technical assistance with the In Situ Indenter and S. Hostettler of Synton-MDP AG, Nidau, Switzerland for help with the joint development of the heated indenter tips used in this work. SP acknowledges equipment funding from NSF MRI # 1726897 and DOE DE-NE0008739 , and research funding from NSF CMMI # 1841331 for this work.
This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract 89233218CNA000001 .
Part of this research was sponsored by the US Army Research Office (ARO) and was accomplished under Grant Number: W911NF-19-1-0389 . The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of ARO or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein.
© 2020 Elsevier B.V.
- Activation energy
- High temperature deformation