Determining the temperature field of selective laser melting process for different heat source paths

• Online Access: http://hdl.handle.net/2047/D20236954

The temperature field of Selective Laser Melting (SLM) process for two different patterns was investigated to find out which pattern is more effective to reduce the temperature gradient. A three-dimensional finite difference simulation model has been investigated with MATLAB to simulate the transient temperature field of powder bed, Inconel 718, including phase change. The goals of this thesis are developing mathematical formulations to generate moving heat source paths and comparing the temperature gradients created by Hilbert and raster curves. Hilbert pattern tends to hover over a local neighborhood longer than raster case. This phenomenon reduces local temperature gradient, and consequently reduces thermal and residual stresses in a solidified metal part. The obtained results show Hilbert pattern has less steep temperature gradient than raster scan due to the relatively slow phase change pace caused by elbow-shaped parts of the pattern.