Laser powder bed fusion of a novel CoCuFeMnNiTi high entropy alloy: processing and characterization

In the present work the possibility of processing a CoCuFeMnNiTi high entropy alloy by laser powder bed fusion (LPBF) is explored. Such composition was specifically tailored with the aim of allowing the precipitation of strengthening second phases during post-processing ageing treatment. A suitable processing window was found by varying processing parameters and the obtained material was characterized under different perspectives. The as-built material consists of a single face centred cubic phase, whose ageing behaviour appears to be influenced by the experienced rapid solidification conditions. The correlation between the resulting microstructures and the corresponding mechanical properties was studied by means of hardness tests, calorimetric analyses and scanning electron microscopy. Finally, the mechanical response of the alloy was analysed, so as to investigate the activation of various plastic deformation mechanisms under different combinations of deformation extent and heat treatment condition.