Compression strength and fracture mechanism of a hierarchical porous yttria-stabilized zirconia microsphere prepared using electro-spraying associated with phase inversion technique

The compression strength and breakage mechanism of a hierarchical porous sphere in hundred-micron size were investigated in the present work. 3 mol% yttria-stabilized zirconia (YSZ) microspheres were prepared by electro-spraying associated with phase inversion (ES-PI) technique. The characteristic compression strengths of the ES-PI microspheres were measured by quasi-static uniaxial compression test, which increased from 19 MPa to 155 MPa as the sintering temperature increased from 1100 °C to 1400 °C. With the similar porosity, the compression strength of the hierarchical structure microsphere was almost three times higher than that of the hollow microsphere. Further, the breakage mechanism of the ES-PI microspheres was proposed by the honeycomb model of cellular materials, which suggested that the breakage of the ES-PI microsphere initiated from the elastic instability of the walls around the finger-like pores. These findings can help the mechanical performance optimization for ceramic microspheres with lightweight structure.