Investigation of Relationship between Instrumented Indentation Hardness and Vickers Hardness

Geometry analysis of ideal Berkovich indentor and ideal Vickers indentor shows that there should be an approximate functional relation:Vickers hardness Hv is equal to nominal hardness Hn divided by 1.08,namely HV=Hn/1.08. Aimed at uniaxial tensile experimental data of 37 carbon steel materials,instrumented indentation experiments are simulated with the ABAQUS finite element software package. From these finite element computations,nominal hardness is derived. Hence,Vickers hardness are determined by substituting the nominal hardness obtained in finite element simulation into the first unmodified functional relation. The value of Vickers hardness calculated from nominal hardness is proved to be in agreement with the experimentally determined Vickers hardness data. Based on this relationship,it is not only possible to compare instrumented indentation hardness with conventional hardness directly,but also can be further adopted to estimate the conventional hardness for materials on small scales such as thin films materials and nanometer materials.