Bioinspired alumina/reduced graphene oxide fibrous monolithic ceramic and its fracture responses

Abstract

Natural composites have very simple compositions and complex hierarchical architectures consisting of several different levels. These features simultaneously endow them with strength, toughness, functional adaptation, and damage‐healing characteristics. Inspired by the microstructural features of natural materials, this work successfully fabricated Al2O3/reduced graphene oxide (rGO) fibrous monolithic ceramics with bamboo‐like structures by introducing a thin graphene oxide around Al2O3 fiber cells to form the rGO boundary phase. The detailed evolutions of the crack extension and fracture responses were investigated by a J‐integral method, and these bamboo‐like composites demonstrated high structural reliability with excellent damage tolerance and progressive plastic failure behavior. With the fiber cell diameter of 0.6 mm, such composites exhibited fracture toughness (29.46 ± 3.04 MPa m1/2) and work of fracture (799 ± 127 J m−2) that were 475% and 1075% higher than those of the monolithic Al2O3 ceramic, respectively. Their excellent fracture‐resistant behavior was attributed to the hierarchical architectures that provide crack deflection, delamination, and load redistribution. The results also established the structure‐activity relationships to guide the design and fabrication of these bamboo‐like composites.

Bioinspired PcBN/hBN fibrous monolithic ceramic: High-temperature crack resistance responses and self-lubricating performances

“…The crack growth resistance was calculated through the J-integral method, and the crack extension length was measured by a compliance method. The detailed calculation was given in our previous paper [11] and the ASTM E1820-05a standard [27]. The typical R-curves of the PcBN/hBN fibrous monolithic ceramics are plotted in Fig.…”

“…It consisted of ceramic fiber cells and cell boundaries around the fiber cells, and has been extensively studied because of its great freedom and flexibility for structural design. The long fiber-reinforced structure can endow composite ceramics with non-brittle fracture characteristics and high toughness due to the confluence of extrinsic toughening mechanisms acting on different scales [10,11]. Our previous research demonstrated that Al 2 O 3 /rGO fibrous monolithic ceramics exhibited excellent crack resistance and progressive failure behavior with a high fracture toughness (29.46 MPam 1/2 ) and work of fracture (WOF) (799 J/m 2 ), which are 475% and 1075% higher than those of the monolithic Al 2 O 3 ceramic, respectively [11].…”

“…The long fiber-reinforced structure can endow composite ceramics with non-brittle fracture characteristics and high toughness due to the confluence of extrinsic toughening mechanisms acting on different scales [10,11]. Our previous research demonstrated that Al 2 O 3 /rGO fibrous monolithic ceramics exhibited excellent crack resistance and progressive failure behavior with a high fracture toughness (29.46 MPam 1/2 ) and work of fracture (WOF) (799 J/m 2 ), which are 475% and 1075% higher than those of the monolithic Al 2 O 3 ceramic, respectively [11]. This was attributed that the unique architecture can "shield" cracks from the applied loads through shear delamination, crack deflection along cell boundaries, and crack branches, resulting in rising crack resistance curve (R-curve) behaviors during fracture [11].…”

A Review on Development of Ceramic-Graphene Based Nanohybrid Composite Systems in Biological Applications

“…The presence of RGO boundaries between Al 2 O 3 fiber cells resulted in superior friction reduction and wear resistance, with stable friction coefficients. Fracture responses of bioinspired RGO/Al 2 O 3 fibrous monolithic ceramic were also investigated in work ( Chen et al, 2020a ). The investigated nanocomposite was characterized by progressive plastic failure behavior, excellent damage tolerance and high structural reliability due to complex hierarchical architectures with several different levels.…”

Bioinspired Design of Graphene‐Based Materials

“…In particular, a fibrous monolithic ceramic consisting of Al 2 O 3 fibers surrounded by rGO "cell boundaries" shows good strength and outstanding fracture toughness perpendicular to the fiber direction, although not in the parallel direction due to the weak interfaces. [176] A clever structure can also be used to improve this aspect, maximizing adhesion between a reinforcing filler material and its matrix. For instance, the mechanical strength of a Cu-CNT composite for load-bearing can be much improved by changing the geometry of the filler to a leaf-like structure, with a strong and stiff CNT midrib surrounded by GO nanoribbons whose high surface area and hydrophilic functional groups improve the interfacial bonding.…”