Experimental Research On Ultrasonic/Fused Deposition Composite Additive Manufacturing Of Polylactic Acid

Fused Deposition Additive Manufacturing(FDM)technology is widely used in aerospace,automotive,construction,and daily life due to its low cost,simple operation,many types of molding materials,and low pollution during printing.However,due to the limited bonding force between the wires in the forming process,the mechanical properties of the formed samples are generally poor,which limits their further development and application in various fields.Therefore,by exploring the influence mechanism of ultrasonic vibration on the mechanical properties enhancement of fused deposition samples,this paper combines ultrasonic plastic welding technology with fused deposition additive manufacturing molding technology,and proposes a molding method for ultrasonic additive manufacturing of heterogeneous materials.Research work in the following areas:(1)The mechanism of ultrasonic vibration on the strengthening of fused deposition molding samples was explored.Under the condition of ensuring the same molding quality of the sample,the effect of ultrasonic strengthening times on the mechanical properties of the sample was studied,and it was found that the tensile strength of the sample showed a slight downward trend with the increase of the ultrasonic frequency,but it was still higher than that without ultrasonication.Strengthen the tensile strength of the sample;The effects of welding time and ultrasonic strengthening times,ultrasonic strengthening and static load compression on the mechanical properties of the samples were compared and analyzed.The results show that the tensile strength and bending strength of the ultrasonic-strengthened samples with a welding time of 0.5 s are higher than those with a welding time of 0.25 s.The second ultrasonic strengthening of the sample,the increase rate of the tensile strength of the sample by ultrasonic strengthening is about twice the increase rate of the tensile strength of the sample by static load compression.The effect of vibration on improving the mechanical properties of FDM molded samples.(2)The influence mechanism of fused deposition forming process parameters on the mechanical properties of ultrasonic strengthened samples was studied,and the effect of forming parameters on ultrasonic strengthening was analyzed by changing the thickness,printing angle and filling angle of the fused deposition samples during the ultrasonic strengthening process.The research results show that with the increase of the thickness of the sample,the improvement rate of ultrasonic on the tensile strength of the sample will decrease significantly;the tensile strength and flexural strength of the sample with a printing angle of 15° increased by ultrasonic is the largest;The tensile strength of the sample with an angle of 45°/-45° has the largest improvement.Combined with the experimental results of the microscopic characterization of the cross-section of the sample,the influence of the molding process parameters on the mechanical properties of the ultrasonically strengthened FDM molding sample is revealed.(3)Based on the systematic research on the influence mechanism of ultrasonic process parameters and molding process parameters on the strengthening of FDM molding,using the ultrasonic welding mechanism of solid dissimilar materials,it is proposed to enhance the mechanical properties of FDM molding samples while adding materials to manufacture heterogeneous materials.The method of forming the part.The experimental study shows that the fused deposition molding sample has ultrasonic weldability,and the fused deposition molding sheet is welded and strengthened layer by layer.Formed a good intermolecular bond with the layers,based on this,a method of sealing the metal tape in the polymer was proposed to realize the layer-by-layer accumulation molding process of the heterogeneous material combined with the polymer and the metal,and the sample molding process was explored.Influence mechanism of mechanical properties and shape memory properties of parts.In this paper,experimental research is carried out by applying ultrasonic energy to fused deposition additive manufacturing technology,and the strengthening law and action mechanism of ultrasonic on the mechanical properties of fused deposition samples are explored,and it is confirmed that the fused deposition samples have ultrasonic weldability.The layer-by-layer strengthening and welding molding of the sample is realized,and the metal is sealed in it,and the sample combining metal and polymer is realized,which is of certain significance for broadening the application field of fused deposition technology.