Dynamic response of wrought and additively manufactured nickel-based alloys to high velocity impacts of laser-launched flyers

Abstract

Although nickel-based superalloys are widely used in the industry, their response to shock loading is still rarely investigated. Here, the impacts of laser-launched flyers were used to study the dynamic behavior of a Rene 65 superalloy under shock pressures of about 10 GPa at very high strain rates of about 106 s−1. Three types of samples, wrought or additively manufactured (laser powder bed fusion) and subjected to different heat treatment conditions, were investigated. These experiments allowed the measurement of the Hugoniot elastic limit (compressive yield strength) and the spall (tensile) strength, both in upper ranges compared with the most common metals. Post-recovery analyses involving various techniques provided insight into dynamic failure with a combination of transgranular ductile fracture and intergranular cracks with preferential nucleation sites, strongly dependent on the different microstructures related to fabrication routes and thermal treatments.