Sintering during Electron Beam-Powder Bed Fusion (EB-PBF) of Ti6Al4V Alloy

The partial sinter between the powder particles during the electron beam – powder bed fusion (EB-PBF) process is fundamental to guarantee adequate thermal and electrical conductivities and conduct the process safely. The sintering degree is tuned by using the process parameters that, at the present day, are mainly optimised with an experimental trial and error approach. Simulation has proven the capability to reduce costs and time related to parameter optimisation. In the current work, a phase field model was developed to simulate sintering during the EB-PBF process. The novelty lies in simulating the sintering process under non isothermal conditions which emulate the heating of the powder due to the preheating and subsequent temperature decrease due to the layer additions. The results show a strong influence of the thermal history on the neck growth and dimension, which differ significantly with respect to the traditional approach to the sintering simulation which considers only constant temperature.