Reinforcement of bone china by the addition of sepiolite nano-fibers

The work attempts to investigate the effect of sepiolite nano-fibers addition on mechanical properties of bone china bodies. Compared with the traditional toughening fibers, the sepiolite nano-fiber has two main advantages: One is that the chemical composition of sepiolite mineral and the chemical composition of bone china raw materials are similar. So it can be used as one of the main components of bone china formulations directly. The other is that the sepiolite is a kind of cheap mineral resources, which will decrease the cost of the toughening ceramics. The flexural strength and fracture toughness were tested by three point bending method and single edge notched beam method, and the microstructure of the bone china was studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscope (TEM). The results showed that 2 wt% sepiolite fiber addition could increase the bending strength of the ceramic bodies. There were two toughening mechanisms in the reinforced ceramic. One was the fiber pull-out. The other was the weak interface mechanism. Plenty of micro-cracks came into being at the weak interface to consume most of the elastic strain energy to prevent main crack from spreading.