Correlation between Shock Wave-induced Indentations and Tensile Strength

Abstract

Cost-efficient and high-throughput material development processes and process chains are needed to meet the on-going demand for new metallic structural materials. Material development involves not only the processing of new material compositions, but also the material characterization. Hence, novel high-throughput screening methods are a promising approach to identify new beneficial material compositions. These methods do not aim to understand the mechanisms of new material compositions. Instead, these methods offer descriptive values, which are correlated with material properties. Here, an indentation method is presented, which is based on laser-induced shock waves. With a high intensity pulsed transversely excited atmospheric-pressure CO2 laser, a shock wave is induced on top of an indenter. The impulse of the shock wave pushes the indenter inside a test material. The created indentations correlate highly with the material hardness measured by conventional techniques. In this study, different descriptive values are extracted and analyzed with respect to the material’s tensile strength (determined with standard tensile tests). Indentations were created in aluminum samples (alloy EN AW-6082), which were heat-treated in different ways. The strongest correlation has been found between the tensile strength and the sink-in and pile-up height instead of the indentation depth or diameter.