On the indentation size effect in spherical indentation

Temperature dependence of the indentation size effect

The influence of temperature on the indentation size effect is explored experimentally. Copper is indented on a custom-built high-temperature nanoindenter, at temperatures between ambient and 200 0C, in an inert atmosphere that precludes oxidation. Over this range of temperatures, the size effect is reduced considerably, suggesting that thermal activation plays a major role in determining the l...

Interpretations of Indentation Size

For very shallow indentations in W, Al, Au, and Fe-3wt%Si single crystals, hardness decreased with increasing depth irrespective of increasing or decreasing strain gradients. As such, strain gradient theory appears insufficient to explain the indentation size effect (ISE) at depths less than several hundred nanometers. Present research links the ISE to a ratio between the energy of newly create...

Spherical indentation of elastic-plastic solids

The finite-element method is used to perform an accurate numerical study of the normal indentation of an elastic-plastic half-space by a rigid sphere. The effects of elasticity and strain-hardening rate of the half-space are explored, and the role of friction is assessed by analysing the limiting cases of frictionless contact and sticking friction. Indentation maps are constructed with axes of ...

On the measurement of stress–strain curves by spherical indentation

It has been proposed that with the appropriate models, instrumented indentation test (IIT) data can be reduced to yield the uniaxial stress–strain behavior of the test material. However, very little work has been done to directly compare the results from uniaxial tension and spherical indentation experiments. In this work, indentation and uniaxial tension experiments have been performed on the ...

Spherical Indentation Hardness of Shape Memory Alloys