Influence of laser deposition patterns on part distortion, interior quality and mechanical properties by laser solid forming (LSF)

Abstract

Present work applied a kind of new deposition pattern, fractal deposition pattern, in the LSF process. The influences of different depositing patterns (fractal, offset and raster) on the parts’ deformation, interior quality and mechanical properties are also investigated. The finite element method (FEM) simulation results show that the offsetout (the offset from the outside to the inside) and fractal deposition patterns generate the temperature distribution with the circular and eccentric circle symmetry at the end of deposition process, respectively. There are smaller temperature gradients using these two kinds of deposition patterns than those by the raster and offsetin (the offset from the inside to the outside) deposition patterns. It is also found that the magnitude of the transient temperature gradient has a critical effect on part distortion during LSF process. The fractal deposition pattern generates the smallest parts’ deformation, followed by offsetout. The parts interior quality investigation with fractal and offsetout deposition patterns shows that the overlap should be increased to 50% to avoid pore defects. Moreover, we find that adopting arc path instead of square path at the corner locations and “semi-spot vibration” strategy for the offset and fractal deposition patterns respectively can produce better LSFed parts’ quality.