The determination of the relationship between strain and microhardness by means of visioplasticity

The determination of strain values by means of microhardness measurements is a useful technique in that it can be used to measure plastic strains either on the surface or within the body of a specimen or structural component. A method is described whereby a calibration curve between strain and microhardness can be obtained by use of the visioplasticity technique. The curve thus obtained is valid for complex stress and strain states and for high strains. The microhardness was found to be a single valued function of the true effective strain independent of how this strain was produced. Agreement was found between the microhardness and values calculated from the flow stress.