Effect of spontaneous polarization of tourmaline on the grain growth behavior of 3YSZ powder

This paper introduces a new method for adjusting the particle size of ZrO2 powder through the electric field effect of tourmaline. The 3 mol% yttria‐stabilized ZrO2 (3YSZ) powder was prepared by using ZrOCl2∙8H2O, YCl3∙6H2O, NaOH, and nano‐tourmaline powder as raw materials through direct precipitation. The powder was characterized with thermogravimetric‐differential scanning calorimeter, X‐ray diffraction, Brunauere‐Emmette‐Teller, Fourier transform infrared, scanning electron microscope, and transmission electron microscope, and the mechanism of tourmaline in the process of powder preparation was also discussed. Findings demonstrate that the electric field generated by spontaneous polarization of tourmaline can control the size of ZrO2 crystal grains, improve the dispersibility of the powder, and promote the stability of ZrO2 in the tetragonal phase. When the electric intensity of tourmaline is 9.02 × 106 V/m, and the addition amount is 2.5 vol%, tourmaline/3YSZ powders are mainly tetragonal phase, and the grain size is the smallest, with an average crystallite size of 19 nm. Then the mechanical properties of tourmaline/3YSZ ceramics were tested. Compared with 3YSZ ceramics without tourmaline, the flexural strength and fracture toughness were improved by 39.5% and 35.8%.