Compression Tests at High Strain Rate on 3D-Printed CuCrZr Alloy Specimens - Material Model Calibration

Abstract

CuCrZr alloy is used to produce actively cooled components for high heat flux elements of beamlines and for heat sink of plasma facing components in nuclear fusion devices such as ITER and DEMO. It has an excellent thermal conductivity and specific mechanical strength, together with a high electrical conductivity that is giving high push to its use. Recently, CuCrZr alloy was also considered as an attractive material for Additive Manufacturing, leading to extend its application in the field of strain rate studies. As a matter of fact, its strain rate dependency is playing an important role for vertical target plasma-facing units components uses as heat sink in the ITER divertor or as structural material for actively cooled plasma facing components. This paper describes the results obtained by quasi-static and dynamic compression tests carried out on CuCrZr specimens produced by laser Powder Bed Fusion (PBF), with Selective Laser Melting (SLM) technology. Quasi-static tests have been conducted by means a servo-hydraulic tensile machine, while a direct tension-compression split Hopkinson bar has been used to perform the tests at high strain rate. Since dedicated heat treatments are required to obtain optimal combination of strength, ductility, and conductivity, some of the specimens have been heated up to 560 – 580 °C for 4 – 5 h and then cooled in air. Eventually, the calibration of the most appropriate constitutive models for 3D-printed CuCrZr alloy deformed at high strain rate has been carried out by means an inverse analytical procedure.