Effect Mechanism Of Tourmaline On The Synthesis And Properties Of Nano Zirconia Powder

With the advent of the 5G communication era,zirconia（ZrO₂）ceramic with high toughness,high wear resistance and no signal shielding has become the first choice for smartphone backplane materials.With the improvement of mobile phone performance requirements,the preparation of nano zirconia powder with ultra-fine,good dispersibility and stable crystal form is one of the hot spots in current ceramic research.In this work,a new method for regulating the synthesis and properties of nano zirconia powders by the electric field effect of tourmaline mineral materials is proposed.The 3 mol%yttrium oxide stabilized ZrO₂（3YSZ）powder was obtained,the micro-morphology and performance test of the nano 3YSZ/tourmaline ceramic powder were carried out,and the action mechanism of nano tourmaline in the powder preparation process was discussed.（1）The effects of the amount of tourmaline added and the calcination temperature on the microscopic morphology of the synthesized nano 3YSZ powder were studied.The zirconia precursor was prepared by adding different amounts of nano tourmaline powder by direct precipitation method,and then calcined to form nano 3YSZ/tourmaline powder.When the calcination temperature is 600℃,the tetragonal phase content of nano3YSZ/tourmaline powder is 99.78%.At the same time,the addition of tourmaline can refine the 3YSZ powder,making it evenly dispersed without agglomeration.When the addition amount of tourmaline is 2.5 vol%,the S_BET of the 3YSZ powder is 37.7 m²/g,and the average particle size is 19 nm.（2）To study the effect of tourmaline addition and sintering temperature on the mechanical properties of 3YSZ ceramics.When the addition amount of tourmaline was 2.5vol%and the sintering temperature was 1300℃,the 3YSZ/tourmaline ceramic had the best mechanical properties,with a flexural strength of 932 MPa and a fracture toughness of10.29 MPa·m^1/2.Compared with zirconia ceramics,the flexural strength and fracture toughness are increased by 39.5%and 35.8%.Through the observation of the micro-morphology of the ceramic fracture,it is mainly transgranular fracture,without pores and good compactness.Therefore,the addition of tourmaline can effectively improve the mechanical properties of 3YSZ ceramics.（3）The influence mechanism of the spontaneous polarization of tourmaline on the synthesis process of nano 3YSZ powder was studied.The study found that the stronger the spontaneous polarization of tourmaline,the better the performance of the nano 3YSZ powder.During the nucleation process of the nano 3YSZ powder,due to the existence of the spontaneous polarization of tourmaline,the two ends of the tourmaline particles in the precursor solution Anions and cations are attracted to make nucleation more uniform.At the same time,the electric field effect generated by the spontaneous polarizability of tourmaline can increase the free energy in the nucleation process,decrease the activation energy of diffusion,increase the nucleation rate and reduce the growth rate,and form more nucleation sites in the solution,making the preparation powder refinement.