The effect of graphene oxide on the mechanical properties of cBN composites fabricated by HTHP method

Conventional cubic boron nitride (cBN) composites suffer from high brittleness and poor machinability. Here, we use graphene to tackle these problems. In this paper, cBN/graphene oxide (GO) composites with the addition of Al-SiC were prepared by high temperature and high pressure sintering method. The fracture toughness of cBN/1.5 wt% GO composites increased by 27.5% compared to that of the monolithic cBN composites. The improvement of fracture toughness is ascribed to crack deflection, graphene interface sliding, and GO pull-out and bridging. The bending strength of the composites improved from 564.2 to 696.9 MPa, which can be attributed to the load bearing of GO and strong bonding between GO and cBN matrix.