Improving the surface quality of material extrusion additive manufacturing parts by using ultrasonic-vibration machining

Material extrusion (ME) technique has been one of the most popular additive manufacturing techniques because of its environmental friendliness, low cost, simple operation, and so forth. However, significant surface defects occur on ME parts due to the discontinuity between adjacent layers. For this reason, a new method, using ultrasonic-vibration machining, was innovatively proposed to improve the ME parts' surface quality. A theoretical surface roughness (SR) model of the ME parts processed by using ultrasonic vibration was established. An ultrasonic-vibrating ME equipment was then set up by refitting an ordinary one and the samples built without and with ultrasonic-vibration machining utilized were prepared, respectively. With the laser microscope, the built parts' SR was tested and determined. Compared the predicted SR results with the measured ones, the theoretical model was verified. The influence of different ultrasonic vibration on the surface quality of ME parts was also discussed, clarifying the corresponding mechanism.