Numerical Simulation On Selective Laser Sintering Process Of Polymer Powder

Selective Laser Sintering (SLS) is a kind of rapid prototyping manufacturing technology, which sinter solid powder together to directly form the 3D component with laser thermal resource and with the separate layer manufacture thinking. It has bright future. In this paper ANSYS software have been used and its special APDL tool also have been employed to program so that the temperature and stress distribution of polymer powder SLS have been analyzed.First, the characters of powder SLS forming have been analyzed: transfer of thermal resource, instantaneity of heating, centrality of heating district, big gradient, change of physical property from powder to solid, and influence of sintering history on performance. The influences of material and processing parameters on forming have been summarized and the effective film coefficient also has been discussed.Second, the load and movement of laser thermal resource, which energy distribution is Gauss one, have been realized by compile APDL program. The dynamic temperature distribution has been simulated. The one layer sintering has two methods, same direction way and S-shaped way. The peak value of temperature of S-shaped way sintering is higher than the one of same direction way. Toward one certain node, it only has got one peak temperature when the node positioned at center of sintering path; if the node is between the two sintering path it will has two peak temperatures. And the time interval depends on the sintering method and the length of sintering path. Temperature distribution of given paths at different time have been analyzed and their way of changing and character was decided by moving thermal resource.At last, elementary simulation and analysis of the stress distribution of sintering and deformation have been committed. The moving laser thermal resource, which energy distribution is Gauss one, made the non-uniform temperature distribution. So the shrinkage and expansion are non-uniform and thermal stress is produced which induced final deformation and warp of component.