  The thermal and mechanical behaviors of powders are important for various
additive manufacturing technologies. For powder bed fusion, capturing the
temperature profile and the packing structure of the powders prior to melting
is challenging due to both the various pathways of heat transfer and the
complicated properties of powder system. Furthermore, these two effects can be
coupled due to the temperature dependence of particle properties. This study
addresses this challenge using a discrete element model that simulates
non-spherical particles with thermal properties in powder spreading. Thermal
conduction and radiation are introduced to a multi-sphere particle formulation
for capturing the heat transfer among irregular-shaped powders, which have
temperature-dependent elastic properties. The model is utilized to simulate the
spreading of pre-heated PA12 powder through a hot substrate representing the
part under manufacturing. Differences in the temperature profiles were found in
the spreading cases with different particle shapes, spreading speed, and
temperature dependence of the elastic moduli. The temperature of particles
below the spreading blade is found to be dependent on the kinematics of the
heap of particles in front, which eventually is influenced by the
temperature-dependent properties of the particles.
