Spontaneous Coagulation Casting and Comprehensive Properties of ZTA ceramics

Spontaneous coagulation casting (SCC) has been proved to be a forming method for producing green bodies with high density and high uniformity. In this work, ZTA (zirconia toughened alumina) composite ceramics with different YSZ (yttria partially stabilized zirconia) content were prepared by means of SCC for the first time. A systematic comparative study was carried out to investigate the green body properties, mechanical properties, friction and wear properties of ZTA ceramics prepared with SCC and dry pressing (DP) forming methods. ZTA ceramics prepared by means of SCC have higher green body density and superior mechanical properties as well as friction and wear properties compared to those formed with the DP method. In addition, with the increase of YSZ content, the flexural strength of the ZTA ceramics gradually increases, while the fracture toughness decreases and the Vickers hardness first increases and then decreases. Meanwhile, the average friction coefficient gradually increases, and the wear rate exhibits the opposite change trend to the Vickers hardness, reaching the lowest value when the YSZ content is 20 wt%.