Studies Of Additive Manufacturing Of Shape Memory Poly (Ether-Ether-Ketone) And Its Performance

The combination of additive manufacturing and shape memory polymers has become a new trend.As a shape memory polymer with high temperature resistance,radiation resistance,corrosion resistance and good mechanical properties,Poly(ether-ether-ketone)(PEEK)has a wide range of application prospects in many fields.Yet,additive manufacturing of PEEK remains challenging and unfulfilled because of the intrinsic high modulus and high processing temperature.At present,most of the research have focused on the mechanical performance of PEEK parts.The effect of additive manufacturing process and structural design of PEEK on its shape memory performance are rarely mentioned.PEEK is a promising candidate that meets the stringent requirements for aerospace and biomedicine applications.The research on the shape memory properties and additive manufacturing process of PEEK can bring out the full potential of the material,providing support and reference for the manufacturing and applications of PEEK,and promoting the multifunctional development of the devices.Aiming at the application and development requirements of PEEK,we systematically investigate the effect of different process parameters on the corresponding shape memory performance,including temperature control,heat treatment method and inner layer structure.The effects and principles of variables on the shape memory performance of PEEK are summarized from the aspects of material crystallization behavior,molecular motion,macrostructure performance,etc.In our study,the highest shape fixity ratio that we can achieve is 99%,and the highest shape recovery ratio is 87%.Through the control of processing parameters,the shape recovery ratio of PEEK can be adjusted within a range of 20% when the shape fixity ratio is maintained at a level above 90%.Secondly,we design and manufacture a series of structural samples of PEEK with different densities and unit structures.Combined with simulation analysis and experimental testing,the influence of different structures on the mechanical properties and shape memory performance of PEEK are explored.It is found that the ratio of the modulus of the honeycomb structure of the three densities roughly corresponds to the ratio of the area of each unit.For different unit structures,the shape fixity ratio is maintained at about 100%,and the shape recovery ratio is closely related to the internal stress of the structures during deformation.Among them,the triangular unit structure shows the highest shape recovery ratio of 77%.Finally,this article verifies the shape memory effect and high temperature resistance of the PEEK parts,and further,by repeating the incomplete recovery process under high-strength deformation,the difference of the permanent form and the original printed form of PEEK has been realized and applied.