Shape Effects of Indenter on the Depth-Sensing Indentation
It is revealed that the conventional reduced modulus used in depth-sensing indentation tests is invalid for a flat-ended cylindrical indenter due to the fact that the contact area during the loading is a constant irrelative to load. The load-displacement curve of flat punch is related to the length of the punch and the ratio of the elastic modulus of the indenter to the specimen (the modulus ratio Ei/E). Furthermore, theoretic analysis and finite element simulation demonstrated that, for conical indenter, the measured hardness from depth-sensing indentation tests would increase with increasing modulus ratio because the load increased with the ratio for the same displacement.
Yiwang Bao, Li Tian and Jianghong Gong
X. Y. Shi et al., "Shape Effects of Indenter on the Depth-Sensing Indentation", Advanced Materials Research, Vol. 177, pp. 105-108, 2011