Materials characterization and classification on the basis of materials pile-up surrounding the indentation

The ball indentation technique (BIT) has been used to classify various engineering materials on the basis of observed pile-up/sink-in in materials, surrounding the indentation. In respect of revealed pile-up, viz., prominent, moderate and negligible, the materials could be classified into three respective groups. The dependence of the pile-up on the yield ratio and the strain-hardening exponent of materials have also been established as a novel concept. The actual indentation diameters (both plastic and total) differ from the diameters calculated from the depth of indentation measured by linear variable transducers (LVDT). This difference is due to the accumulation of materials (pile-up) surrounding the indentation. The methodology to determine the correction factor, to be incorporated in the measurement of actual diameter, has been highlighted and is compared with the reported approach.