  This work proposes an extension of phase change and latent heat models for
the simulation of metal powder bed fusion additive manufacturing processes on
the macroscale and compares different models with respect to accuracy and
numerical efficiency. Specifically, a systematic formulation of phase fraction
variables is proposed relying either on temperature- or enthalpy-based
interpolation schemes. Moreover, two well-known schemes for the numerical
treatment of latent heat, namely the apparent capacity and the so-called heat
integration scheme, are critically reviewed and compared with respect to
numerical efficiency and overall accuracy. Eventually, a novel variant of the
heat integration scheme is proposed that allows to directly control efficiency
and accuracy by means of a user-defined tolerance. Depending on the chosen
tolerance, it is shown that this novel approach offers increased numerical
efficiency for a given level of accuracy or improved accuracy for a given level
of numerical efficiency as compared to the apparent capacity and the original
heat integration scheme. The investigation and comparison of all considered
schemes is based on a series of numerical test cases that are representative
for application scenarios in metal powder bed fusion additive manufacturing.
