Abstract
Initially invented in the 1980s, nanoindentation based techniques have made significant strides in the past few decades at characterizing materials and devices on nano and micro scales. Sometimes referred to as instrumented or depth-sensing indentation, nanoindentation measures hardness values of specimens beyond the material size and volume limitations of conventional hardness tests. It has become the choice for mechanical characterization of thin films, coatings and small-volume materials.
Nanoindentation relies on precise control of the applied force to an indenter tip and fine measurement of the indenter displacement into a material, or vice versa, precise control of the indenter displacement while measuring force needed to reach that displacement. The generated force-displacement curve during nanoindentation carries distinctive and fingerprint information about mechanical deformation of the tested material specimen. Based on an established and widely accepted Oliver and Pharr model and method, nanohardness and elastic modulus of the material can be derived from the force-displacement curve. Because of its important role played in the nanotechnology boom and implementation, nanoindentation has been further developed and has evolved considerably over time, expanding well beyond just measuring nanohardness and elastic modulus.
In this presentation, state-of-the-art nanoindentation techniques beyond nanohardness and elastic modulus measurements will be covered. Introduction and reviews on quasi-static nanoindentation for fracture toughness, express property mapping, nanocompression test, stress-strain curve derivation, creep, and stress relaxation will be provided. In addition, exemplary case study results on dynamic nanoindentation of visco-elastic materials will also be discussed.
About the Speaker
Dr. Dehua Yang is a Fellow of ASM International and an award-winning materials scientist, accomplished corporate executive, and founder of a successful nanotechnology development and testing services company. As the President and the Chief Scientist of Ebatco, he oversees Ebatco’s ISO/IEC 17025:2017 accredited lab services. Prior to founding Ebatco, he was the Vice President for Hysitron Inc.
Dr. Yang is a Trustee of the Board of Trustees of ASM International. He is the Immediate Past Chair of the ASM Handbook Committee, and he was the Chair of ASM Technical Book Committee. Dr. Yang was the technical editor for Tribology & Lubrication Technology for several years.
Dr. Yang has a Ph. D. degree in Physical Chemistry, more than 60 peer-reviewed publications and 7 issued US patents. The products he designed and managed at Hysitron, the nanoTensile 5000 and 3D OmniProbe, won the 2007 Micro/Nano 25 Award and 2005 Nano 50 Award, respectively.