High-strain-rate behavior of 3D-printed CuCrZr

CuCrZr alloys reach high mechanical properties by thermal (e.g. supersaturated temper and ageing), mechanical (e.g. ECAP) or thermomechanical treatments (solution annealing, cold working and ageing). This alloy can be considered a functional material and it can be exploited in different application fields, thanks to a combination of thermal, electrical and strength properties. In this work, tensile tests at different strain rates have been conducted on CuCrZr specimens produced by additive manufacturing. As-built and heat-treated conditions have been considered. The quasi-static tests have been performed by an electro-mechanical testing machine, while the high strain rate tests have been performed by a Direct Tension Split Hopkinson Bar. The geometry of the samples has been selected based on the requirement of the dynamic tests, and the same geometry was used in quasi-static tests for the sake of comparison. High-speed imaging has been used to capture the real strain of the specimens. The results showed a limited positive strain rate sensitivity in terms of flow stress for as-built conditions, whereas negative strain rate sensitivity was observed for the heat-treated samples; but positive sensitivity in terms of ductility was observed for as-built, whereas uncertain results occurred in the case of heat-treated material.