Interfaces friction effect of sliding contact on nanoindentation test

The nanoindenation testing system has been extensively applied to determine mechanical properties of thin film presently. However, the contact surface between the indenter and the thin film may arise a sliding friction. The existing report ignores such a friction force effect at the contact surface. This study will present several experimental results to demonstrate the existing of the friction force between the tip of the indenter and the test sample. In this regard, the effect of the sliding friction on thin film mechanical property measurement will be discussed. According to the experiment results, the friction force effect is influenced by the indent depth. In addition, the interface friction force is more significant for the brittle material due to its larger elastic restoring force. The ignorance of the friction effect may lead to significant error when extracting elastic modulus of thin films from the indentation test.