Lead Zirconate Titanate Ceramic Prepared By Direct Ink Writing And Piezoelectric Property Of Composites

As a typical smart material,piezoelectric ceramics are widely used in the fields of sensing and driving,smart structure and energy harvesting.The traditional preparation methods of piezoelectric ceramic devices are difficult to meet the three-dimensional direction of no dead angle,high sensitivity detection and high fidelity signal output.There is an urgent need for piezoelectric ceramics to have complex structure,customized shape and multi-function integration.Based on this,this research adopts the direct ink writing(DIW),and develops the PZT piezoelectric ceramic organic slurry with appropriate rheological properties by optimizing the slurry design.Combined with the secondary auxiliary shaping of 3D flexible ceramic green bodies,the forming and densification of unsupported 3D ceramic support with bending and spiral structure are realized.It is confirmed that the DIW combined with secondary auxiliary shaping can fabricate complex piezoelectric ceramic components.At the same time,the effects of different composite types and ceramic phase content on the properties of piezoelectric composites are systematically studied,and the piezoelectric composites with tight twophase bonding and good properties are obtained;The feasibility of preparing metal electrode piezoelectric ceramic materials by co-extrusion direct writing method based on feed needle barrel design and needle nozzle design was preliminarily explored.The main research contents are as follows:(1)The effects of binder,plasticizer,dispersant and solid content in PZT organic DIW slurry on its rheological properties,slurry viscosity and storage modulus were studied,and the corresponding relationships between rheological properties and paste printing performance,printing process parameters and molding structure characteristics were constructed.The results show that the significant factors affecting the storage modulus of slurry are plasticizer and solid content,and the significant factors affecting the viscosity of slurry are solid content and binder content;the most suitable combination of slurry components and solid content for DIW process is: solid content 80.0 wt.%,binder content 5.0 wt.%,dispersant content 2.0 wt.%,plasticizer content 1.0 wt.%.(2)The effects of plasticizer,binder content and three-dimensional structure design in PZT organic DIW slurry on the secondary shaping ability of green bodies were studied.Combined with TG / DSC thermal analysis,the discharge and sintering process of green bodies were optimized.The results show that the best slurry component content combination of green bodies secondary shaping ability should be plasticizer content of 1.5 wt.% and binder content of 5 wt.%;It is proved that the secondary shaping ability of green bodies can be significantly optimized through the reasonable design of three-dimensional structure;High density 3D-PZT ceramics with density better than 98% were obtained.(3)3D-PZT piezoelectric composites were prepared.The effects of3 D structure and ceramic phase content of spiral,3-3 and 3-1 ceramics on the electrical and acoustic properties of the composites were studied,and the co-extrusion DIW process of nickel electrode PZT piezoelectric ceramics was explored.The results show that the acoustic impedance of helical piezoelectric composites is lower than 20 MRayls;The electromechanical coupling coefficient is high,which is higher than 60%;When the ceramic phase content of 3-3 piezoelectric composites is 50～55vol.%,the comprehensive properties are the best;The electromechanical coupling coefficient of 3-1 piezoelectric composite is high.When the volume fraction of PZT is 75.90 vol.%,the electromechanical coupling coefficient in the thickness direction reaches 72.82%.