Investigation of design factors effect on the surface quality in powder bed fusion methods

In this study, the geometrical errors at angular and curved surfaces will be examined that is a basic problem of AM technologies, especially in powder bed fusion methods. The staircase effect is determined based on part orientation and layer thickness. The staircase error model based on triangular functions and the model of mean primary profile (Pa) is developed based on an experimental study in the literature. In this study, an algorithm is created that used to investigate the surface quality and calculate staircase errors and the mean primary profile. The results explained that with the increasing of the layer thickness the staircase effect will be increased. When the layer thickness reduced from 30μm to 20μm for the same model, it is observed that the error decreased by 25%. Also, it was determined that the error decreases with the increasing of part orientation angle. More ever, with the increasing radius of the vertical curvilinear models, the error will be decreasing. When the radius of curvature increased from 10mm to 15mm, the average error decreased by 34%, 50% and 33.5% at 20, 30 ve 40 μm layer thickness respectively. This study determined that there is not only a staircase affecting the surface quality but, the balling effect is also stated to be an effective factor. A small orientation angles, the staircase effect was found to be very effective on surface quality. However, at large orientation angles, the surface quality is very much affected by the balling effect.