Microstructure and anisotropic mechanical properties of graphene nanoplatelet toughened biphasic calcium phosphate composite

Investigating the mechanical behavior of hydroxyapatite-reduced graphene oxide nanocomposite under different loading rates

“…In all published reports, the mechanical behavior of these nanocomposites against the specified amount of loading has been investigated, but no report has been published on the mechanical behavior of these materials against load changes [20][21][22][23]. The mechanisms that lead to increased fracture toughness in these nanocomposites include graphene pull-out, crack deflection, graphene bridging, and inhibition of crack growth by graphene sheets [24,25]. One of the mechanical properties indicators of materials is their behavior against the variable loads applied to the materials at varying rates.…”

Spark plasma sintering of graphene reinforced hydroxyapatite composites

“…So far only a few reports have been published on the use of graphene additive to improve the mechanical properties of hydroxyapatite ceramics [23]. Zhao et al [24] prepared graphene platelet/biphasic calcium phosphate composites by hot pressing. He reported a considerable improvement in terms of mechanical properties like bending strength and fracture toughness using 1.5 wt% GNPs.…”

Preparation and mechanical properties of Si3N4 nanocomposites reinforced by Si3N4@rGO particles

“…Crack branching is a very common toughening mechanism in all studied composites containing graphene. 54 As shown in Figure 12F, when the crack propagated through the Si 3 N 4 matrix, it met with the rGO sheets, experienced a substantial resistance and was deflected in-plane. In this study, the rGO sheet was firmly anchored or wrapped underneath the Si 3 N 4 grain, resulting in the formation of a continuous three-dimensional rGO wall along the grain boundary that can not only divert crack propagation in one plane, but also cause crack deflection in three dimensions.…”

“…In this case, the energy required to pull out the two-dimensional rGO sheets was greater than that of the other nanofibers due to the wrinkled rGO sheets wrapping around the Si 3 N 4 grain and the increased contact area between the rGO sheet and the matrix. 54 As shown in Figure 12F, when the crack propagated through the Si 3 N 4 matrix, it met with the rGO sheets, experienced a substantial resistance and was deflected in-plane. [50][51][52] Figure 12D shows that the rGO sheets acting as elastic bridges can effectively bridge the crack, reducing the local stress at the crack tip and blocking the crack propagation and enhancing the toughness of nanocomposites.…”