Boron nitride nanosheets reinforced glass matrix composites

Abstract

The effect of reinforcing boron nitride nanosheets (BNNSs) on the mechanical properties of an amorphous borosilicate glass (BS) matrix was studied. The BNNSs were prepared using liquid exfoliation method and characterised by transmission electron microscopy, scanning electron microscopy and X-ray diffraction (XRD) analysis. The average length was ,0.5 mm, and thickness of the nanosheets was between 4 and 30 layers. These BNNSs were used to prepare BS-BNNS composite with different loading concentrations of 1, 2.5 and 5 mass-% (i.e. 1.395, 3.705 and 7.32 vol.-%). Spark plasma sintering (SPS) was used to densify these composites to avoid structural damages to the BNNSs and/or crystallisation within the composite sample during high temperature processing. The BNNSs were found to be evenly distributed in the composites matrix and were found to be aligned in an orientation perpendicular to the direction of the applied force in SPS. The mechanical properties including fracture toughness, flexural strength and elastic modulus were measured. Both fracture toughness and flexural strength increased linearly with increasing concentration of BNNSs in BS glass. There was an enhancement of ,45% in the fracture toughness (1.10 MPa.m 1/2 ) as well as flexural strength (118.82 MPa) with the addition of only 5 mass-% loading of BNNSs compared to BS glass (0.76 MPa.m 1/2 ; 82.16 MPa). The toughening mechanisms developed in the composites because of the reinforcement of BNNSs were thoroughly investigated.

Mechanisms of TiB2 and graphite nucleation during TiC–B4C high temperature interaction

“…Theoretical and experimental research, presented in all the mentioned studies, have showed that the influence of low-modulus phase on the material characteristics is closely related to sizes, shapes, and the distribution of the soft inclusions within the solid matrix. As it can be concluded from numerous works [6,9,11,17,18], soft particles can not only "weaken" material but also improve its fracture resistance. This is achieved when cracks are arrested by blunting crack tips at low-Ehigh-E material interfaces.…”

“…The inclusions positive influence has been demonstrated by numerous investigations of heteromodulus ceramics (HMC): Si3N4-BN [5,6], TiC-C [2,7,8], B4C-BN [4,9], SiC-BN [10], TiB2-TiC-C [11], ZrB2-SiC-C [12 -15], HfB2-HfC-C [16] and glass-BN [17]. Theoretical and experimental research, presented in all the mentioned studies, have showed that the influence of low-modulus phase on the material characteristics is closely related to sizes, shapes, and the distribution of the soft inclusions within the solid matrix.…”

2D boron nitride nanosheets for polymer composite materials

“…For example, Young's modulus and tensile strength of polyacrylic acid (PAA) hydrogel (water content 70 wt.%) composites were increased by 244% and 57%, respectively, when 0.5 g L −1 BNNSs was added to the PAA hydrogel 112 . This excellent reinforcement 49,67,81,92,102,105,[108][109][110]112,113,132,140,152,156,183,233,236,[245][246][247][248][249] . Fig.…”

Mechanical and tribological properties of nanocomposites incorporated with two-dimensional materials

“…9. Moreover, it was shown that the introduction of BN results in the strengthening and toughening of ceramic composites [28,82,175].…”