Study On The Influence Of 3D Printing Parameters On The Mechanical Properties And Molding Quality Of PLA

3D printing technology is a rapid prototyping technology,which has the advantages of fast forming speed and short manufacturing cycle.With its own technological advantages,this technology has been widely used in aerospace?medical?automotive? machinery and other fields.However,compared with the traditional manufacturing process,the mechanical properties,surface roughness and dimensional accuracy of the technology are relatively poor.Only by improving these problems can the 3D printing technology be developed faster and wider.This paper has carried out the following four parts of research work on the above issues:(1)This paper firstly conducted a detailed study on the molding principle,printing system composition,process flow and molding materials of FDM 3D printing technology.(2)In order to improve the mechanical properties of 3D printed parts,this paper analyzes the effects of different printing parameters including print layer thickness,printing temperature,filling rate,outer contour circle and printing speed on tensile strength and elastic modulus of 3D printed specimens.It was found that the filling rate had the greatest influence on the tensile strength of the test piece,and for the elastic modulus,the filling rate and the printing temperature were the main influence parameters,and the printing layer thickness,the outer contour circle number and the printing speed were also on the molded test piece.The tensile strength and modulus of elasticity have a certain influence.(3)The study analyzed the reasonable printing speed and the speed ratio of the extrusion speed,and the effect of the printing speed on the surface roughness of the test piece in this interval.It was found that the ratio of printing speed to extrusion speed was too large or too slow,which would cause the printing to fail.The reasonable speed ratio range was from 0.8 to 1.2,and the printing speed had a great influence on the surface roughness of the molded specimen.If the printing speed is too slow or too fast,the surface roughness of the test piece will increase sharply.The printing speed also directly affects the processing time,so it is reasonable to choose a suitable printing speed.(4)The factors affecting the dimensional accuracy of the molded parts of FDM principle 3D printing technology are analyzed and analyzed,and the dimensional accuracy of the molded parts is optimized by orthogonal test design.The effects of printing temperature,printing speed,and printing layer thickness on the dimensional accuracy in the horizontal and vertical directions of the molded article were mainly studied.The results show that the printing speed has the greatest influence on the horizontal dimension accuracy of the FDM printing parts,followed by the printing layer thickness,and the printing temperature horizontal dimension dimensional accuracy is less affected.The optimal printing speed reference value is 70mm/s,which is optimal.The printing temperature is 200 ?and the printing layer thickness is 0.15 mm;The vertical dimension accuracy affects the printing speed,print layer thickness and printing temperature from the largest to the smallest.The optimal printing speed is also 70mm/s.In this direction,the optimal printing temperature is 200?,the print thickness is 0.15 mm.