216 / 2021-04-01 12:19:20

Theoretical and experimental study on improving the bonding neck of Material extrusion (ME) products by applied vibration

Material extrusion technique; use vibration; bonding neck; theoretical model; scanning electron microscope

Material extrusion (ME) technique is one of the most widely used additive manufacturing technology today, capable of producing 3D geometric entities with arbitrary complex shapes. The bonding neck between the extruded material filaments constituting the ME product has a vital influence on its forming quality. In this paper, theory and experiments are combined to explore the method of using vibration to improve the bonding neck, that is, using piezoelectric ceramic to apply longitudinal (i.e. along the direction of melt flow) sinusoidal vibration field to the extrusion liquefier to increase the bonding neck, so as to achieve the improvement of the product’s forming quality. A theoretical model of the bonding neck was set up based on the viscous sintering phenomenon of the extruded material filaments; The refitting of the vibrating ME equipment and the preparation of samples were then completed, and the scanning electron microscope (SEM) were carried out, analyzing the bonding neck of the samples; Through the comparison between theoretical and experimental results, the theoretical model was validated and the influencing rule of different types of vibration on the bonding neck was determined. The results show that the bonding neck will be increased with vibration applied, and it will be further increased with the increase of vibration frequency or amplitude. Therefore, introducing vibration into ME process helps improve the forming quality of the built products.