Study On The Influence Of Sintering Aids On The Suntering And Properties Of PZT And PLZT Ceramics

At present,as a kind of functional material,piezoelectric ceramics have a wide range of applications in daily life.Lead zirconate titanate（PZT）is one of the most widely-developed piezoelectric materials,and it plays an irreplaceable role in the fields of electronics,aerospace,biomedicine,and engineering.There are various preparation methods of PZT piezoelectric ceramics,and the sintering equipment is becoming more and more advanced,and the performance obtained is getting better and better.However,from the perspective of production cost and production efficiency,people still prefer some high production efficiency,Production process with low production cost.Generally speaking,people will improve the PZT production process from three different ways,the first is powder synthesis;the second is sintering equipment;and the third is the addition of sintering aids.In this paper,from the perspective of adding sintering aids,the effect of the types and amounts of sintering aids on the properties of PZT ceramics is studied.First of all,this article takes PbZr_0.52Ti_0.48O₃ as the research object under the conditions of solid-phase synthesis of powder and pressureless sintering to conduct process research.Investigate the effects of the powder phases obtained at different calcination temperatures,the time and method of different secondary ball milling on the micro morphology and ceramic properties of PZT ceramics,the effect of different lead elements on PZT ceramics,and explore the best sintering temperature And the holding time,and finally study the properties of PZT ceramics with different ratios of zirconium to titanium.Through the above research,the best process of PZT under the conditions of this laboratory is determined:the selected composition is the ratio of zirconium to titanium 54:46,the pre-sintering temperature of the PZT powder is 840℃,and the holding time is 2h;the excess of 2mol%lead element is selected,The secondary ball milling method of wet milling is selected,the ball milling time is 9h;the sintering temperature is 1200℃,and the heat preservation is 2h.And under this condition,the density of PZT ceramics is 7.38g/cm³,and the piezoelectric coefficient is 161p C/N.Sintering aids can not only promote the sintering of ceramics,but also can dope to improve the performance of ceramics.This paper selected five sintering aids including Li₂CO₃,Sb₂O₃,CaO,SrO,Nb₂O₅,and set the addition amount of 0.5wt%,1.0wt%,1.5wt%,2.0wt%,2.5wt%,3.0wt%to study their The influence of PZT ceramics.Studies have shown that Li₂CO₃ can form a liquid phase at high temperatures to increase the density of ceramics,but excessive Li₂CO₃ will precipitate at the grain boundaries and affect the performance of the ceramics.When 2.0wt%Li₂CO₃ is added,the density of PZT ceramics can be significantly increased.Comprehensive performanceρ=7.77g/cm³,d₃₃=102p C/N,ε_r=910,tanδ=0.21;Sb₂O₃ added to PZT ceramics can be found to increase the ceramic density and refine the grain,but it is not conducive to ceramic piezoelectric Performance improvement,when 2.0wt%Sb₂O₃ is added,its comprehensive performance isρ=7.73g/cm³,d₃₃=67p C/N,ε_r=2261,tanδ=0.025;after adding Ca O,it is found that the addition of Ca O will make the ceramic dense The main reason for the decrease is that Ca O cannot completely dissolve into the PZT crystal lattice,but aggregates on the crystal surface,which seriously affects its performance.When 0.5wt%Ca O is added,its comprehensive performance isρ=7.36g/cm³,d₃₃=141pC/N,ε_r=839,tanδ=0.00040;After adding SrO,it is found that SrO has little effect on the properties of PZT ceramics,but SrO can promote the growth of crystal grains.When 1.5wt%SrO,its comprehensive performance isρ=7.01g/cm³,d₃₃=187p C/N,εr=1197,tanδ=0.011;when 1.5wt%Nb₂O₅ is added,the piezoelectric properties of PZT ceramics are greatly improved.It is found by SEM that Nb₂O₅ can refine the crystal grains.Its comprehensive performance isρ=7.46g/cm³,d₃₃=282pC/N,εr=1216,and tanδ=0.027.Under the conditions of solid-phase method and pressureless sintering,the preparation process of PLZT ceramics is that the lead element excess is 7 mol%,the pre-sintering temperature is 1100℃,the holding temperature is 1200℃,and the holding time is 2 hours.The comprehensive performance of PLZT isρ=7.71g/cm³,d₃₃=192p C/N,tanδ=0.013,and the absorbance is 18.2%.After adding 2.0wt%Li2CO3,its comprehensive performance isρ=7.44g/cm³,d₃₃=113pC/N,and the absorbance is17%.When 2wt%Li₂CO₃ and 2wt%Sb₂O₃ are added,the overall performance isρ=7.26g/cm3,d₃₃=102p C/N,εr=1300,tanδ=0.025,and the absorbance is 15%.