| Undergoing evolution for millions of years, shells as one of natural biologicalmaterials, have realized perfect unification of their structure and mechanical properties.Nacre is the mai stacked microstructure found in the interior of many mollusc shells.Due to the inorganic-organic composition, highly ordered stacking manners and innersub-micro, nacre can sustain significant inelastic deformation and exhibits amazingtoughness, comparing with the man-made composition. Therefore, the preparation ofimitation shell nacre structure composite materials has become one of the mostimmportant methods to improve the toughnesses of ceramic.This paper took the nacre of Anodonta as the object, and studied the composition,structure and characteristics of morphology by scanning electron microscopy （SEM）.The characteristics of morphology and the thermal behavior were researched in detail byx-ray diffraction （XRD）, thermogravimetric analysis （TG） and thermogravimetricanalysis （DTA）. The mechanical properties of nacre were studied by3-point bendingtest, compressive test and nanoindentation. Finally, through investigating therelationship between the structure and performance of nacre, it was concluded that themicro-stacking structure and the adhesion of organic phase were an important factor fordesigning composites of nacreous structure.Inspirated from the nacre we studied, the Al2O3/epoxy resin composites withnacre-inspired hierarchical complexity were prepared by vacuum infusion technique.And this paper took porous Al2O3ceramics as inorganic phase, and epoxy curingsystemas as the organic phase and prepreg. To imitate the structure and properties ofnacre, this article compared the proportion of different curing resin, regulated thecontent of ceramic phase, introducted the structure of ceramic bridge and improves theintegrated state of interface.Several experimental resultst are concluded as follows. With the increase of thecuring agent in the resin system, the flexural strength and fracture work increased firstand then decreased. The optimum curing agent content was1:1（wt）. The strength andtoughness of the material was mainly decided by the ratio of the thickness of ceramiclayers to lamellar spacing （d/λ）. Increasing the ceramic content could increase thethickness ratio. Compared to40wt%and50wt%ceramic content of the compositesconclude that50wt%ceramic phase of composites had highest strength and fracturework. Two lamellar structure ceramics were prepared, one was with ceramic bridgeareand the other is without.The introduction of the ceramic bridge structure increased theresistance of the relative sliding between the lamellar and crack propagation resistance,which led to increase the strength and fracture work. Therefore, the composities with 1:1ratio of curing agent content,50%ceramic content and ceramic bridge structure hadthe highest strength and fracture work which were62.24MPa and3.43KJ/m2.The silane coupling agent KH-550treated the Al2O3porous ceramic.We found thatmodified Al2O3is from hydrophilic to pro-oil.It’s better filled to the epoxy resin. Salinecoupling agent modified Al2O3porous ceramic enhanced the strength and fracture workof composites. Therefore, after modification of ceramic surface the strength and fracturework of composites were63.11MPa and3.57KJ/m2。... |
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