Direct Ink Writing Of Epoxy-based Composite With Exceptional Strength And Toughness

Due to the exceptional strength,easy to modify and lightweight,epoxy-based composites have been widely applied as automotive and critical aerospace component.However,the brittle nature of epoxy resin leads to poor resistance to crack initiation and propagation,significantly hindering their applications as high-performance composites.Therefore,it is of vital importance to develop an effective strategy to improve the toughness while retaining the high strength of epoxy composites.Herein,takes the process as a breakthrough,from the perspective of the internal structure of the composites,we develop an architectured composite lattice with simultaneous high toughness and strength through a 3D printing technique.(1)Firstly,the optimal ratio of ink for epoxy composites is clarified by FTIR and rheological characterisation,and the physical and chemical parameters and printable properties of the epoxy composite printing are explored.An architectured composite lattice construction method for epoxy composites is investigated,and the extrusion process and moulding morphology of the paste are precisely regulated through the control of printing parameters to provide for the subsequent precision design and efficient fabrication of the lattice.(2)Secondly,the integrated manufacturing process-structure-property regulation method of epoxy composite lattice is investigated.Through the regulation of process parameters,epoxy composite lattices with different structural parameters are formed,and the key factors controlling their strength and toughness are analysed,and the influence of structural parameters on the mechanical properties of epoxy composite lattices is clarified.Through the analysis of the mechanics and structure of the epoxy composite lattice under ageing conditions,the influence law of the external environment on its performance is explored.Through crosssectional analysis and numerical simulations,the mechanism of the regular porous structure on the synergistic enhancement of strength and toughness of epoxy composites is fully revealed.(3)Finally,the forming process and formability control methods of multifunctional epoxy composite lattices are investigated.The multifunctional epoxy composite lattices were formed through the synergistic regulation of printing and process,and the multi-material applicability of the mechanical properties of the lattice structure was verified through the analysis of the mechanical and electromagnetic shielding properties of different structured conductive epoxy composite lattices,the electromagnetic shielding properties of different structured conductive epoxy composite lattices were explored,the influence law of structure on the electromagnetic shielding properties of conductive epoxy composite lattices was elucidated,and the mechanism of the influence of structure on the electromagnetic shielding performance of conductive epoxy composites lattice is revealed.