Experimental setup for fully coupled kinematic and thermal measurements at the microstructure scale of an AISI 316L steel

In polycrystalline metallic materials, above a certain threshold, mechanical deformations induce plastic strains at the grain scale. The development of plasticity also triggers a thermal dissipation due to local mechanical irreversibilities. These phenomena conduct to a heterogeneous state of deformation and temperature which has never been simultaneously observed at the micrometric scale. In this paper, an original experimental setup is presented in order to obtain fully coupled measurements. The objective is to get at the same time strain and temperature fields in the same zone at the microstructure scale of an AISI 316L austenitic stainless steel specimen during a tensile test. The fully coupled measurements underscore the relationship between the local plastic and thermal heterogeneities during the first stages of the deformation until a more general plastic state of the specimen. These results may also be used to perform energy balances at the micrometric scale.