【摘要】：反鐵電體因具有獨特的電滯回線以及相轉(zhuǎn)變特征,可被用于高儲能密度脈沖電容器中。本文研究的是鋯錫鈦酸鉛鋇鑭(PBLZST)反鐵電陶瓷,該體系的陶瓷具有優(yōu)異的儲能性能。目前有諸多手段可用來提高反鐵電陶瓷的儲能密度,例如組分調(diào)控、元素摻雜、成分復合等,然而新的陶瓷燒結(jié)工藝對儲能性能的影響,則尚未得到深入研究。因此,本文采用了熱壓的新工藝,從以下幾個方面研究了PBLZST的儲能性能:首先,本文對熱壓燒結(jié)工藝進行了設計,分別研究了燒結(jié)溫度、保溫時長、熱壓壓力等因素對反鐵電陶瓷性能的影響。實驗結(jié)果表明:熱壓燒結(jié)制備的PBLZST,其燒結(jié)溫度比起普通燒結(jié)可降低近200℃,可在1100℃下燒結(jié)成瓷。同時,保溫時間為2小時,熱壓壓力調(diào)整到70MP時,陶瓷成瓷效果良好。其次,對于鉛基陶瓷體系,燒結(jié)過程始終伴隨著鉛揮發(fā)。本文設計了五組不同鉛過量組分,研究了PbO過量量對熱壓和普通燒結(jié)的PBLZST微觀結(jié)構(gòu)和儲能性能的影響。結(jié)果表明:通過SEM分析,熱壓陶瓷樣品晶粒輪廓清晰,微結(jié)構(gòu)更加均勻,氣孔率低,其中PbO過量量為6mol%的熱壓樣品平均晶粒尺寸為1.8μm,致密度達到99.5%;擊穿場強Weibull分析表明熱壓樣品擊穿場強普遍較高,最高達到180KV/cm;高壓電阻率測試結(jié)果表明熱壓樣品電阻率大于1013Ωm,較普通燒結(jié)樣品高兩個數(shù)量級;熱壓法制備的反鐵電陶瓷樣品,其最高儲能密度達到3.2 J/cm3,該儲能密度是普通燒結(jié)樣品的2倍。由于在熱壓燒結(jié)過程中,樣品通常處于缺氧狀態(tài),燒結(jié)的陶瓷會產(chǎn)生氧缺陷,這影響了陶瓷的電性能。本文通過設計不同的氧化后處理工藝,研究了后期氧處理對PBLZST儲能性能的影響。結(jié)果表明:在850℃下,PBLZST在空氣中氧化3小時,或在氧氣氛下氧化1.5小時(通氧速率為50 mL/min),氧化效果較好。處理后的PBLZST樣品的儲能密度得到進一步提高,達到3.45J/cm3。
[Abstract]:Because of its unique hysteresis loop and phase transition, antiferroelectrics can be used in high energy storage density pulse capacitors. The antiferroelectric ceramics of lead barium zirconium tin titanate lanthanum titanate (PBLZST) are studied in this paper. The ceramics of this system have excellent energy storage properties. At present, there are many ways to improve the energy storage density of antiferroelectric ceramics, such as component control, element doping, composition composite, etc. However, the effect of new sintering process on the energy storage performance has not been further studied. Therefore, the new technology of hot pressing is adopted in this paper, and the energy storage performance of PBLZST is studied from the following aspects: firstly, the hot pressing sintering process is designed, and the sintering temperature and holding time are studied, respectively. The effect of hot pressing pressure on the properties of antiferroelectric ceramics. The experimental results show that the sintering temperature of PBLZST, prepared by hot pressing sintering is about 200 鈩，

本文編號：2243845