Self-assembly of graphene reinforced ZrO2 composites with deformation-sensing performance

Incorporating graphene sheets into the ceramic matrix can induce a fine microstructure with unique interfaces, in which the excellent mechanical and electrical properties of individual sheets are packed and applied in bulk quantities. However, further development of graphene-ceramic composites is hindered by the poor distribution uniformity and structural integrity of 2D sheets as well as high anisotropy. Here, a self-assembly strategy based on electrostatic adsorption is proposed for the homogeneous and nondestructive fabrication of graphene oxide-ZrO2 hybrids. By SPS, dense composites are obtained with improved flexural strength (1187 ± 21 MPa), fracture toughness (8.10 ± 0.04 MPa⋅m1/2) and a percolation threshold below 1 wt%. The common anisotropy in graphene composites is restricted, showing consistent properties on different surfaces. A high correlation between resistance change and deformation has been confirmed, which can be well described by binomial equation. The sensitive and stable sensing performance makes this composite a promising smart material for in-situ self-monitoring.