Research On Interfacial Bonding Strength Between Guide-sleeve And Resin In3d Weaving

To meet requiments of high performance and light weight of parts in aerospace,national defense and military industry, and the problems during woving for compositesuch as complex process, low machine automation, large components and complexcomponents cannot formed, a new method of3D weaving forming for composite isproposed by China Academy of Machinery Science&Technology (CAM), which namedDigital Flexible-oriented Multi-dimensional Weaving Forming. In this method, the guideposts distributed in a reasonable way through2D structure after layering of3D modelcan make the woven fiber get nearer to the contour shape and adjust the density of innerwoven structure. The woven fiber forms into inner mesh grid structure and both innerand outer contour by winding and locking the guide sleeves on the guide posts, in orderto reach the goal of weaving in specific structures. Based on connet between the layersby weaving, Guide sleeve tightly connet between the layers again, thus Z directions isstrengthened by the guide sleeve. Guide sleeve largely enhanced the layer performanceof the composite, and meanwhile, the interfacial bonding strength between guide sleeveand resin matrix is a major factor that affects the mechanical properties of composites.So this thesis study focused on the interface between guide sleeve and resin matrix,specific study on interfacial bonding strength influenced by guide-sleeve material，bumpy ridge structure on guide sleeve and compound process conditions.Comprehensive analysis the properties of several material, this paper choosedaluminum alloy and carbon fiber composite as guide material during this reasearch.Through several test for aluminum alloy, which surface are treated by different process,and carbon fiber composite, such as observation on the surface morphology, contactangle measurement and surface energy calculation， analysis the surface chemicalcomposition, test the length of interface area and test the interfacial shear strength,following results are obtained: the interfacial bonding strength is highest between thealuminum alloy, which surface are treated by phosphoric acid anodic oxidation(PAA)before pickling by HNO3/HF and before alkali erosion by NaOH, and epoxy resin. Thecombination,which between carbon fiber composite and epoxy resin, occurredinterfacial polymerization, so the interfacial bonding strength between carbon fibercomposite and epoxy resin is higher than the shear strength of carbon fiber compositeselves, and during the push-out test, the carbon fiber composite are damaged only.Through the push-out test for bumpy ridge structure of trapezoid and hemicycle, which with diferent character size, following results are obtained: the interfacial shearstrength is increasing followed by contact area, and the second peak load is increasingfollowed by the surface area of bumpy ridge structure, for the second peak load isforming by shearing the epoxy resin, and the interlayer strength is not affected by theshape of bumpy ridge structure, when the character size are same.Through anlysis the interfacial bonding properties between guide sleeve and epoxyresin in different compound process conditions, following results are obtained: accordingto the interfacal adsorption theory, the interfacial bonding strengh between the material,whose surface energy is higher than others, and epoxy resin is higher. In the roomtemperature condition, surface energy of aluminum alloy is higher than carbon fibercomposite, so the interfacial bonding strengh between aluminum alloy and epoxy resin ishigher than the interfacial bonding strengh between carbon fiber composite and epoxyresin. After postcure or forming by high temperature curing, the interfacial bondingstrengh between aluminum alloy and epoxy resin are increased, and the interfacialbonding strengh between carbon fiber composite and epoxy resin are increasedmore.Because of the combination, which between carbon fiber composite and epoxyresin, occurred interfacial polymerization, and the interface between aluminum alloy andepoxy resin mainly combined with mechanical bond.