Research On Mechanical Properties Of PEEK Molding Parts Based On FDM

Poly-Ether-Ether-Ketone(PEEK),as a semi-crystalline and thermoplastic special engineering plastics,has been widely used in the aerospace field due to its high heat resistance,high strength,high modulus and other excellent comprehensive properties.Different from the traditional processing technology,the technology of molding PEEK by the Fused Deposition Modeling(FDM)can achieve the rapid molding of complex parts with high material utilization rate.With the development of the current technology,FDM molding PEEK fits the requirements of the production.This study focuses on the influence of FDM molding process parameters on the mechanical properties of PEEK molding parts,after heat treatment on the PEEK molding parts by FDM,analyzing the influence of the heat treatment process for the mechanical properties of the PEEK molding parts,which lays a foundation for the study on the controllable mechanical properties of PEEK forming parts by FDM.First of all,according to the process of FDM molding PEEK and the characteristics of PEEK material,this study systematically analyzed the factors affecting the mechanical properties of the PEEK molding parts,and summarized the influence rules of wire preparation process,molding process parameters and heat treatment process on the mechanical properties of the PEEK molding parts.The mobility of wire and melt transition characteristic temperature of the PEEK wire were measured,which provides a theoretical basis for the study of mechanical properties of PEEK molding parts.Secondly,this thesis studies the influences of printing direction,nozzle temperature and cooling method on the mechanical properties of the PEEK molding parts,and analyzed the influence of molding process parameters on the crystallization degree of the PEEK using differential scanning calorimetry(DSC).The reasons of the mechanical properties change caused by the forming process parameters were analyzed from the microscopic point of view,and the influence of crystallinity on mechanical properties of the PEEK was determined.Finally,the mechanical properties retention rate of the PEEK molded parts after heat heating rate and holding time on the mechanical properties of the PEEK molded parts was studied.The reasons of the mechanical properties change caused by the heat treatment were explained via the microscopic perspectives of crystallinity and fracture morphology.The primary and secondary relationship of the influence of the heat treatment process parameters on the mechanical properties of PEEK molding parts was obtained,and the optimal matched process parameters were obtained respectively.