Nanoindentation is a widely used tool for probing the mechanical properties of materials at the nanoscale. The analysis of the load-displacement curve obtained from nanoindentation provides the hardness and elastic modulus of the material. While hardness is a useful parameter for comparing different alloys and understanding tribological behavior, yield strength is a more useful parameter for alloy design and application in general. The yield strength of a nanoindentation-tested material can be estimated by combining the hardness result with the Tabor factor. This approach is well-established for homogeneous and isotropic materials; however, the application of the approach to recently developed laminated nanocomposites requires a better understanding of the plasticity under nanoindentation. Due to the complicated stress state and the nonhomogeneous geometry of the nanolaminated structure, there is a need to employ numerical methods for this analysis. In this study, the mechanical behavior of a model system of nanolaminated Cu-Nb under nanoindentation was investigated, through modeling the test using finite element method. The force-controlled simulation provided the load-displacement curve that would be obtained from an actual experiment, and Oliver-Pharr method was employed to obtain the hardness of the nanocomposite. The results show that the rule-of-mixture is a good approximation for estimating the nanoindentation hardness of the composites, if the mechanical properties of the constituents are known.
mechanical testing nanoindentation finite element modeling nanostructured materials nanolaminated materials
Primary Language | English |
---|---|
Subjects | Engineering |
Journal Section | Articles |
Authors | |
Publication Date | December 31, 2018 |
Published in Issue | Year 2018 Volume: 19 Issue: 4 |