Spall fracture in wrought and additively manufactured Ni-based superalloys subjected to high pressure laser-driven shocks

The impact response of Nickel-based superalloys is still poorly documented with respect to the industrial interest in these materials. Here, laser-driven shocks are used to study and compare the dynamic behavior of Rene 65 superalloy with different microstructures at very high strain rates in the order of 10⁶ s⁻¹. Rene 65 specimens studied here are either in cast and wrought or additively manufactured (laser powder bed fusion) and subjected to different heat treatment conditions. Time-resolved velocity measurements provide the yield strength (Hugoniot elastic limit) and spall strength (resistance to dynamic tension) of each variant. In addition, post-recovery characterization gives insight into the initiation and propagation of dynamic fracture, which are shown to depend on the different manufacturing routes and thermal histories.