Metal Additive Manufacturing Conference 2018

The paper describes the influence of increasing inclination angle on the surface quality of the downskin of 3D-printed cubic samples via Laser Powder Bed Melting. The series of samples was printed using 316L powder with increasing inclination angle in respect to the baseplate. In order to observe a balling effect and a decreasing surface quality the samples were printed with no supporting structures placed on the downskin. The one-track tests were performed using an in-house developed test stand and characterising with linearly increasing depth of the powder bed, which enables to physically simulate specific solidification conditions during the printing procedure of samples with increasing inclination angle. A balling phenomenon was quantified and compared using the roughness test and it was found to be dependent on the inclination angle. The microstructural investigation was done using LOM, SEM and EBSD methods in order to compare the microstructural changes with respect to the changing inclination angle. The roughness comparison of cubic samples with one-track samples brought meaningful information about the influence of the solidification conditions of the molten pool on the maximum printing angle of supportless surfaces.