Study On Preparation Of Titanate Template By Eutectic Solidification

Piezoelectric materials are a type of electronic functional material capable of converting mechanical energy into electrical energy and vice versa.They play a crucial role in various piezoelectric devices.Textured piezoelectric ceramics,as compared to conventional piezoelectric ceramics,exhibit higher piezoelectric constants and do not suffer from the segregation issues observed in piezoelectric single crystals.Currently,most textured ceramics are produced using the Templated Grain Growth（TGG）technique.However,the existing template preparation process is complex,expensive,and unsuitable for large-scale production.This research aims to achieve the rapid preparation of a titanate template by leveraging the growth principle of the eutectic solidification layer.The study investigates the impact of process parameters,such as ingredients,superheat,and cooling rate,on the phase structure,morphology,and size of the titanate template during the eutectic solidification process.Based on these findings,the prepared titanate samples are separated and treated to obtain a plate titanate template suitable for ceramic texturing.Based on the KF-PbTiO₃ eutectic phase diagram,the PbTiO₃ template was prepared using the eutectic solidification method.The study systematically investigated the influence of process parameters,such as ingredients,superheat,and cooling rate,on the phase structure,morphology,and size of the PbTiO₃ samples.XRD analysis revealed that the samples obtained under different process parameters exhibited a pure perovskite phase.The microstructure examination of the samples indicated that when the ingredients were composed of 4.8 mol%PbTiO₃ and 95.2 mol%KF,the PbTiO₃ sample predominantly exhibited a flake-like morphology.As the superheat increased,the cooling rate decreased,and the circulating heating times reduced,the PbTiO₃sample exhibited increased flaking and larger size.The maximum diameter-to-thickness ratio reached 400:1.To address the issue of mixed morphology in the PbTiO₃ samples,a two-step screening method combining wedge screens and square hole screens was employed.By adjusting the size of each screen,the separation process controlled the size of the obtained template.Consequently,a PbTiO₃ template with a diameter ranging from 200 to 400μm and a thickness of1 to 10μm was achieved.This template meets the requirements of the TGG method for the preparation of textured ceramics.Based on the KF-BaTiO₃ eutectic phase diagram,the BaTiO₃ template was prepared using the eutectic solidification method.The study systematically investigated the influence of process parameters,including composition,superheat,and cooling rate,on the phase structure,morphology,and size of BaTiO₃ samples.It was observed that when the ingredients were composed of 1.9 mol%BaTiO₃ and 98.1 mol%KF,the BaTiO₃ sample predominantly exhibited a flake-like morphology.With an increase in superheat,a decrease in cooling rate,and a decrease in circulating heating times,the size of the BaTiO₃ sample increased.The maximum diameter-to-thickness ratio reached 200:1,which was more than 10 times that of the BaTiO₃ template prepared using the traditional process.By adding 3 mol%Ti O₂ to the composition,the shape of the BaTiO₃ sample transformed into a needle-like morphology.The maximum length-to-thickness ratio achieved was 40:1.A two-step sieving method was employed to obtain the BaTiO₃template with a diameter ranging from 100 to 200μm and a thickness of 1 to 10μm.This template fulfilled the requirements for the preparation of textured ceramics using the TGG method.