Novel approach for fabricating horizontal overhanging structures in selective laser melting

The fabrication of overhanging structure is difficult in Selective laser melting. Currently, temporary supports must be installed when fabricating horizontal overhanging structures, but this method inevitably results in additional waste. This paper presents an original study for the fabrication of horizontal overhanging structure. By using a defocused laser, a new structure layer was successfully printed directly on the powder bed, which was used as the initial layer of a horizontal overhanging structure to replace the traditional supports. As a feasibility check, a closed box with a large horizontal top was printed. The experimental results show that the new approach can significantly reduce the additional waste caused by conventional supports.