CuCrZr alloy obtained via electron-beam powder bed fusion: Microstructural insights and precipitation behaviour

An in-depth characterization of microstructure and mechanical properties of CuCrZr alloy processed by electron beam powder bed fusion (EB-PBF) additive manufacturing technology was performed with the aim to investigate the effect the thermal history of the material during the building process has on the properties of printed parts. Fully dense samples with a relative density up to 99.77 ± 0.04 % were successfully obtained in optimized conditions. The samples in the as-built condition exhibit an anisotropic microstructure dependent on the energetic input. An extensive microstructural transformation occurs alongside the precipitation and segregation of chromium-rich species, driven by the elevated thermal conditions during the deposition process. This unique thermal evolution can be properly investigated and exploited to eliminate the need for further post-processing heat treatments. To identify and quantify the precipitations within the microstructure, scanning and transmission electron microscopy together with electron backscattered diffraction were used.