The invention discloses a
selective laser melting simulation method simultaneously considering
molten pool and
microstructure evolution, which mainly comprises establishment and
calculation methods of
powder laying and a
powder melting and solidification process model, and comprises the following specific steps: setting the geometric dimension and the number of internal
crystal grains of a substrate to generate a polycrystalline substrate; establishing a
discrete element model, simulating a roll shaft
powder spreading process, and obtaining particle information; introducing a sequence parameter, constructing a free
energy density functional, and establishing a heat-flow-
microstructure strong coupling phase field model; constructing a
powder bed geometric model, distributing
grain orientation, and dividing grids for the
powder bed geometric structure; setting material attributes and boundary conditions, and solving the phase field model by a
finite element method; and carrying out
visualization processing on a calculation result to obtain a
molten pool and a
microstructure morphology. Evolution behaviors of the
molten pool and the microstructure in the
selective laser melting process can be simulated at the same time, alternate
simulation and
data transmission of the powder laying process and the
laser scanning process are achieved, and therefore actual
machining production is guided, and technological parameters are optimized.