The invention relates to a multi-material variable-
diameter screw
extrusion 3D printing device. An X-axis driving unit is arranged on a bottom plate, a Y-axis driving unit is arranged on the X-axis driving unit, a printing platform is connected above the Y-axis driving unit, and the X-axis driving unit and the Y-axis driving unit drive the printing platform to move horizontally; and a feeding unit and a Z-axis driving unit are installed on a vertical plate, and the Z-axis driving unit drives a printing unit to vertically ascend and descend.
Slurry is added into a mixing cavity through a feeding
pipe in the hedging direction, and the primary
mixing effect is improved when the
slurry just enters the mixing cavity; a screw adopts a variable-inner-
diameter unequal-depth screw groove design, and when the
slurry is mixed by the variable-
diameter screw, the flowing direction of the
slurry is continuously disturbed, so that the
mixing effect of the slurry is further improved; gaps between screw grooves of a feeding section and a mixing section of the variable-diameter screw and the inner wall of a charging
barrel are gradually reduced, the
extrusion force is continuously increased, and gaps of an
extrusion section are not changed, so that the extrusion uniformity and stability of a high-
viscosity material are ensured.