The adaptive slicing algorithm and its impact on the mechanical property and surface roughness of freeform extrusion parts

ABSTRACT In the process of fused deposition modelling, the layer thickness plays a vital role in determining the surface quality and forming time. If a larger layer thickness is adopted, the molding time will be shorter, as a result, the surface accuracy of the product will be worse at the same time. If a smaller thickness is used, the surface quality of the product can be guaranteed, but the molding time will be very long accordingly. Therefore, there exists conflict between guaranteeing the surface quality and shortening the forming time of the part. This paper adopts adaptive slicing algorithm to solve this conflict. According to the curvature of the model, an appropriate thickness value is adopted automatically where the model curvature is large, a smaller thickness value is necessary, on the contrary, a larger thickness value is used. The tensile strength experiment was made through the specimens of ASTM D638 to study the influence of layer thickness. The temperature of the first six layers in the processing of building was collected. The ultra-depth picture of the cross-sectional area showed that the temperature would affect the neck length between adjacent filaments. Moreover, the surface roughness of the cylinder with different layer thicknesses was measured and the Ra curve figures showed the surface roughness was also influenced by layer thickness. The experiment results suggested the layer thickness was a critical factor in determining mechanical property and surface roughness by changing the layer counts and the neck length between adjacent filaments. It can be noted from the experiments that the adaptive slicing algorithm was not only good at enhancing the surface accuracy and tensile strength, it could also improve the building efficiency.