Preparation of Al2O3 poly-hollow microsphere (PHM) ceramics using Al2O3 PHMs coated with sintering additive via co-precipitation method

In this paper, the Al2O3 poly-hollow microspheres (PHM) were used to prepare novel Al2O3 PHM ceramics. In order to improve the mechanical properties of the Al2O3 PHM ceramics, the Al2O3 PHMs were coated with CaSiO3 sintering additive via co-precipitation method. The effect of CaCl2 solution content on the properties of the Al2O3 PHM ceramics was investigated. With the increase of the CaCl2 solution content, the porosity of the Al2O3 PHM ceramics decreases, while the shrinkage, flexural strength and fracture toughness increase. When the CaCl2 solution content is 8 mL, the flexural strength and fracture toughness of the Al2O3 PHM ceramics are as high as 191.09 MPa and 3.74 MPa·m1/2, respectively. It is found that coating the Al2O3 PHMs with sintering additive via co-precipitation method could effectively improve the properties of the novel Al2O3 PHM ceramics.