Study On The Preparation Of Piezoelectric Ceramics Based On Stereolithography

Piezoelectric ceramics have the properties of piezoelectric,dielectric and elastic,which can realize the conversion between mechanical energy and electric energy.Piezoelectric ceramic is the base material of ultrasonic transducers,piezoelectric transformers,filter and piezoelectric buzzer device and so on.It occupies an important position in the fields of electronic information,machinery industry,instrument and apparatus,medical equipment and so on.Preparation of piezoelectric ceramic based on 3D printing technology has some advantages,such as fast speed,no mold and without machining.And the important advantage is to solve the problem of preparing piezoelectric ceramic with specific complex structure.3D printing technology has extensive application prospect in preparing piezoelectric ultrasonic components.The main contents of this research are preparation of piezoelectric ceramics based on stereolithography technology,including preparation of the widely used PZT piezoelectric ceramics and the promising BNT-based lead-free piezoelectric ceramics.Finally,textured BNT-BT lead-free piezoelectric ceramics have been prepared creatively based on stereolithography technology.The main research contents of this paper are as follows:1.PZT piezoelectric ceramics have been prepared based on stereolithography technology,and the impacts of weight content of ceramics suspensions on the shrinkages,density,microstructure,crystal structure and electric properties of PZT ceramics have been investigated.The results show that green-body has the higher density,and the shrinkages of sintered-body decrease with the PZT content increases.While the relative densitiy of sintered-body were abnormally approximately equal?91.3⁹2.1%?with the weight content increases.The ceramic crystal structure became more stable,electric property increase firstly and then decrease as the PZT content increases.The best electric property is achieved when the weight content is 81.8 wt%,respectively.d₃₃=345 pC/N,k_t=0.53,?_r=1040,tan?=0.020.Furthermore,a two-dimensional ultrasound transducer array was fabricated based on the PZT ceramics with complex structure.The 2D array transducer with center frequency of 2.24 MHz exhibited a-6dB bandwidth of 35%.These results indicate that the 3D-printed ceramics had good potential for the ultrasound transducer applications.2.0.935(Bi_0.5Na_0.5)TiO₃–0.65BaTiO₃?BNT-BT?ceramics with excellent properties near the MPB phase boundary were selected as the matrix,?0.935-x?(Bi_0.5Na_0.5)TiO₃–0.65BaTiO₃-xSrTiO₃?BNT-BT-xST?lead-free piezoelectric ceramics with SrTiO₃ additives have been prepared based on stereolithography technology,and the impacts of SrTiO₃ content on curing depth,microstructure and electric properties of BNT-BT-xST ceramics have been investigated.The results show that with the SrTiO₃ content increases,curing depth of the composite ceramic suspensions increases.As SrTiO₃ content increasing,a core-shell structure with SrTiO₃nucleus was formed in the ceramic grain and grain size decreases gradually,XRD diffraction peaks shift toward the lower diffraction angle slightly,the Curie temperature T_m moves towards lower temperature,the piezoelectric and dielectric properties are degenerated.3.Textured BNT-BT lead-free piezoelectric ceramics have been prepared creatively based on stereolithography technology,and the impacts of cold isostatic pressing technology,template content and template size on orientation degrees and electric properties of ceramics have been investigated.As the synthesis temperature increase,size of Bi₄Ti₃O₁₂ template powders increases;Exerting a skim isostatic pressure on the green body after debinding,increasing content or size of template powder can improve the orientation degrees and electrical performances.But relative density of ceramic would decrease with the size of template powders increase.When the template size is 26.23?m,the biggest orientation degrees of 74.7%and the largest piezoelectric constant d₃₃ of 135 pC/N have obtained.The piezoelectric property is greater than the random oriented BNT-BT ceramics with the composition near MPB phase boundary fabricated based on the traditional pressing technology.The technology of preparing texture piezoelectric ceramics based on stereolithography is an effective method to improve the performance of piezoelectric ceramics.