Influence of friction in material characterization in microindentation measurement

A comprehensive computational study is undertaken to identify the influence of friction in material characterization by indentation measurement based on elasto- plastic solids. The impacts of friction on load versus indentation depth curve, and the values of calculated hardness and Young's modulus in conical and spherical indentations are shown in this paper. The results clearly demonstrate that, for some elasto-plastic materials, the curves of load versus indentation depth obtained either by spherical or conical indenters with different friction coefficients, cannot be distinguished. However, if utilizing the parameter @b (see text for details), to quantify the deformation of piling-up or sinking-in, it is easy to find that the influence of friction on piling-up or sinking-in in indentation is significant. Therefore, the material parameters which are related to the projected area will also have a large error caused by the influence of friction. The maximum differences on hardness and Young's modulus can reach 14.59% and 6.78%, respectively, for some elastic materials shown in this paper. These results do not agree with those from researchers who stated that the instrumented indentation experiments are not significantly affected by friction.

[1]  D. Tabor.  Hardness of Metals , 1937, Nature.

[2]  Zenon Mróz,et al.  Identification of plastic hardening parameters of metals from spherical indentation tests , 2001 .

[3]  S. Youn,et al.  FEA study on nanodeformation behaviors of amorphous silicon and borosilicate considering tip geometry for pit array fabrication , 2005 .

[4]  Subra Suresh,et al.  DETERMINATION OF ELASTOPLASTIC PROPERTIES BY INSTRUMENTED SHARP INDENTATION , 1999 .

[5]  J. Alcalá,et al.  The role of friction on sharp indentation , 2004 .

[6]  Johann Michler,et al.  Determination of plastic properties of metals by instrumented indentation using different sharp indenters , 2003 .

[7]  F. C. Lea.  Hardness of metals , 1936 .

[8]  X. Hernot,et al.  Influence of penetration depth and mechanical properties on contact radius determination for spherical indentation , 2006 .

[9]  G. Pharr,et al.  The correlation of the indentation size effect measured with indenters of various shapes , 2002 .

[10]  G. Pharr,et al.  An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments , 1992 .

[11]  Jianguo Lin,et al.  A study on the determination of plastic properties of metals by instrumented indentation using two sharp indenters , 2007 .

[12]  Subra Suresh,et al.  Computational modeling of the forward and reverse problems in instrumented sharp indentation , 2001 .

[13]  Subra Suresh,et al.  A new method for estimating residual stresses by instrumented sharp indentation , 1998 .

[14]  Xi-Qiao Feng,et al.  Analysis of spherical indentation of superelastic shape memory alloys , 2007 .

[15]  G. Pharr,et al.  A numerical approach to spherical indentation techniques for material property evaluation , 2005 .

[16]  Panayiotis Papadopoulos,et al.  A family of simple two-pass dual formulations for the finite element solution of contact problems , 2007 .

[17]  J. Barbera,et al.  Contact mechanics , 1999 .