Improved shock-reloading technique for dynamic yield strength measurements

The imperfection of shock-reloading experiments has become the main obstacle to measuring the dynamic yield strength of materials under shock compression within the framework of the self-consistent strength-measuring method. In this work, we report an improved shock-reloading technique, in which additional layers of high-hardness materials are used as the backing of the two-layer impactor to eliminate the impactor’s distortion and thus overcome the long-standing debonding issue during launching. This technique has the merits of easy accessibility, no modification of material properties, and being applicable to any materials, therefore providing a practicable and reliable way to obtain high-quality reloading data. As a demonstration, we adopt this technique to shock-reloading experiments in aluminum up to 71 GPa and record high-quality particle-velocity profiles with the details of the quasi-elastic reloading from the initial shocked state. The dynamic yield strengths are then determined using the self-consistent method and found to be consistent with data available in the literature.