Densification behaviour of laser powder bed fusion processed Ti6Al4V: Effects of customized heat treatment (CHT) and build direction

Abstract

The present work exploits the customized heat treatment (CHT) to study the porosity levels of Optical microscopy evaluates the porosity level and microstructure in different conditions. Further, the porosities are classified as inter-micropores (size < 10 µm) and super-micropores (size > 10 µm). Moreover, the XRD technique was used to analyse the different phases that arose during laser powder bed fusion (LPBF) and CHT. The CHT at elevated temperature (1050ºC) helps to reduce the overall porosity level by two times that of as-printed samples due to the sintering self-healing phenomenon. Interestingly, the super-micropores observed in as-printed samples are reduced via CHT, which is favourable for enhancing mechanical properties. Moreover, the refinement of microstructures into different phases after CHT has improved the densification behaviour. (i). Classification and quantifications of the porosities level of LPBF processed Ti6Al4V alloy under both directions due to CHT. (ii). The effect of CHT and its pore self-healing mechanism and microstructure refinement on LPBF processed Ti6Al4V alloy. (iii) This study reveals that the CHT technique can be beneficial in introducing isotropic microstructure and densifying the distinctive LPBF components.