Metals Identification from Instrumented Spherical Indentation Testing

Abstract

A new integrated system consisting of a testing machine, denominated Diaptometro, and of an algorithm for metallic materials identification via instrumented spherical indentation testing is presented. The identification is carried out by analyzing the experimental load – penetration depth curve ( curve) from shallow indentation tests, thus preventing any contact condition effects in the material properties estimation. Accuracy in the experimental data collecting and the curve representation were recognized to be the key factors at the basis of reliable and accurate estimations. A new equipment with accuracies of 0.075% and 0.1% for the penetration depth and indentation load respectively was specifically built-up, whereas a four-terms power expansion is proposed for modeling the curve in the identification procedure. Experimental validation campaigns confirm the effectiveness of the adopted solutions.