本文選題：氧化鋅復(fù)合導電陶瓷 + 組成��； 參考：《陜西科技大學》2017年碩士論文

【摘要】：氧化鋅復(fù)合導電陶瓷是一類在電力電子工業(yè)具有廣泛應(yīng)用前景的功能材料。長期以來,由于制備工藝和理論研究的不足,嚴重制約了這類材料的工業(yè)化生產(chǎn)。本文以ZnO-ZnAl_2O_4-Mg O為基礎(chǔ)體系,深入探討了基體組成以及燒結(jié)溫度對于其顯微結(jié)構(gòu)和電學性能的影響規(guī)律,成功制備出了一類可用于高頻電場、綜合性能較優(yōu)的新型氧化鋅復(fù)合導電陶瓷。文章首先探討了基體組成對于氧化鋅復(fù)合導電陶瓷顯微結(jié)構(gòu)和電學性能的影響規(guī)律。結(jié)果發(fā)現(xiàn):當Mg O的含量為5.00 mol%、燒結(jié)溫度為1320 o C時,通過改變ZnAl_2O_4的含量,可以制備出臨界頻率高于0.67 M Hz、非線性系數(shù)在0.99~1.23范圍內(nèi)、電阻率在11.60~123.48W·cm范圍內(nèi)連續(xù)可調(diào)的氧化鋅復(fù)合導電陶瓷�？紤]到工業(yè)生產(chǎn)過程中Zr4+可能被引入基體,本文在性能較優(yōu)的三元基礎(chǔ)體系中研究了ZrO_2摻雜的影響規(guī)律。結(jié)果發(fā)現(xiàn):摻雜少量的ZrO_2有利于微觀形貌和電學性能的優(yōu)化。當ZrO_2含量為0.30 mol%、燒結(jié)溫度為1320 o C時,試樣的電阻率為19.59W·cm、非線性系數(shù)為1.01、阻溫系數(shù)為-2.60′10-3/o C、臨界頻率為1.20 M Hz。為了克服試樣在致密性以及對燒結(jié)溫度敏感等方面的不足,本文在性能較優(yōu)的基礎(chǔ)體系中引入NiO相進行改性。結(jié)果發(fā)現(xiàn):NiO的添加可以降低燒成溫度,顯著改善試樣的致密性。當NiO含量為7.00 mol%、燒結(jié)溫度為1280 o C時,可以獲得性能較優(yōu)的四元體系氧化鋅復(fù)合導電陶瓷,其電阻率為15.13W·cm、非線性系數(shù)為1.05、阻溫系數(shù)為-1.79′10-3/o C、臨界頻率為1.25 M Hz。此外,Ni2+在ZnO晶格中的固溶可以降低燒結(jié)過程中坯體內(nèi)的溫度梯度,從而顯著地降低了試樣對燒結(jié)溫度的敏感性。在研究燒結(jié)溫度對于試樣電學性能影響的過程中,本文選擇了1280 oC~1400 o C的溫度區(qū)間。結(jié)果發(fā)現(xiàn):燒結(jié)溫度對于氧化鋅復(fù)合導電陶瓷的電學性能產(chǎn)生了顯著影響。溫度升高可以促進致密化過程、引起晶粒和晶界電阻率的顯著降低。與此同時,溫度升高可以削弱界面效應(yīng),引起非線性系數(shù)的降低和臨界頻率的提高。但是過高的燒結(jié)溫度溫度可能會破壞試樣顯微結(jié)構(gòu)的均勻性,造成電學性能的劣化。同時,由于在氧化鋅復(fù)合導電陶瓷中,晶界勢壘較低、不具有活性,因此試樣能夠呈現(xiàn)出線性伏安特性和高頻穩(wěn)定特性。此外,氧化鋅復(fù)合導電陶瓷的導電機理符合“熱激發(fā)”和“滲流導電”模型,基體中存在顯著的Maxwell-Wagner界面極化,這種極化方式維持了穩(wěn)定的晶界效應(yīng)。
[Abstract]:Zinc oxide composite conductive ceramics is a kind of functional materials with wide application prospect in power electronics industry. For a long time, the industrial production of this kind of material has been restricted seriously because of the shortage of preparation technology and theoretical research. In this paper, based on ZnO-ZnAl2O4-MgO system, the effects of matrix composition and sintering temperature on microstructure and electrical properties of ZnO ZnAl2O4-MgO system are discussed. A class of high frequency electric fields have been successfully prepared. New type zinc oxide composite conductive ceramics with better comprehensive properties. In this paper, the effect of matrix composition on microstructure and electrical properties of ZnO composite conductive ceramics is discussed. The results show that when the content of MgO is 5.00mol / L and the sintering temperature is 1320 oC, the critical frequency is higher than 0.67m Hz and the nonlinear coefficient is in the range of 0.991.23 by changing the content of ZnAl2O4. Zinc oxide composite conductive ceramics with continuously adjustable resistivity in the range of 11.60 ~ 123.48 W cm. Considering that Zr4 may be introduced into the matrix during industrial production, the effect of ZrO _ 2 doping in ternary basic system with better performance has been studied in this paper. The results show that doped with a small amount of ZrO _ 2 is beneficial to the optimization of micromorphology and electrical properties. When the content of ZrO2 is 0.30mol / L and the sintering temperature is 1320 OC, the resistivity is 19.59W / cm, the nonlinear coefficient is 1.01and the resistance temperature coefficient is -2.60,10-3 / oC, and the critical frequency is 1.20mHz. In order to overcome the shortage of densification and sensitivity to sintering temperature, nio phase was introduced into the basic system with better properties. The results show that the addition of w / nio can decrease the sintering temperature and improve the densification of the samples. When the nio content is 7.00 mol / L and sintering temperature is 1280 o C, the quaternary ZnO composite conductive ceramics with better properties can be obtained. The resistivity is 15.13 W / cm, the nonlinear coefficient is 1.05, the resistance temperature coefficient is -1.79 / 10 ~ (-3) / o _ (C), and the critical frequency is 1.25m Hz. In addition, the solid solution of Ni2 in ZnO lattice can reduce the temperature gradient of the billet during the sintering process, thus significantly reducing the sensitivity of the sample to the sintering temperature. In the course of studying the influence of sintering temperature on the electrical properties of the sample, the temperature range of 1280 OC / 1400oC is selected. The results show that the sintering temperature has a significant effect on the electrical properties of ZnO composite conductive ceramics. The increase of temperature can promote the densification process and cause the decrease of grain size and grain boundary resistivity. At the same time, the increase of temperature can weaken the interfacial effect and cause the decrease of nonlinear coefficient and the increase of critical frequency. However, too high sintering temperature may destroy the uniformity of microstructure and result in deterioration of electrical properties. At the same time, because the grain boundary barrier is low and the sample is not active in ZnO composite conductive ceramics, the sample can exhibit linear voltammetry and high frequency stability characteristics. In addition, the conductive mechanism of ZnO composite conductive ceramics accords with the "thermal excitation" and "percolation conduction" models, and there is a significant Maxwell-Wagner interfacial polarization in the matrix, which maintains a stable grain boundary effect.
【學位授予單位】：陜西科技大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TQ174.1

【參考文獻】

相關(guān)期刊論文 前10條

1 何愷;吳婕婷;于仁紅;商銚;徐傳孟;牟姝妤;徐東;;ZrO_2摻雜ZnO壓敏瓷的性能及晶粒生長研究[J];電瓷避雷器;2015年04期

2 張寧;劉歡;王曉陽;闞洪敏;龍海波;;SiC-YAG陶瓷復(fù)合材料的燒結(jié)致密性研究[J];硅酸鹽通報;2015年08期

3 于曉華;榮菊;詹肇麟;王遠;;燒結(jié)工藝對ZnO壓敏陶瓷微觀結(jié)構(gòu)與電學性能影響[J];材料熱處理學報;2015年S1期

4 董玉娟;張珂;葉效;易萌;羅雪丹;徐東;;Al_2O_3摻雜ZnO線性電阻的性能及其顯微組織[J];江蘇大學學報(自然科學版);2014年02期

5 何日青;楊傳仁;陳宏偉;張繼華;趙強;;MgO摻雜對ZnO基線性電阻陶瓷性能的影響[J];壓電與聲光;2013年04期

6 許川;馬愛瓊;劉民生;高云琴;;固相反應(yīng)法合成鋅鋁尖晶石[J];硅酸鹽通報;2012年02期

7 史小鋒;樊曰娥;徐東;程曉農(nóng);施利毅;;保溫時間對氧化鋅壓敏瓷組織和電性能的影響[J];河南科技大學學報(自然科學版);2010年06期

8 張兆生;盧振亞;;TiO_2和MgO摻雜的ZnO導電陶瓷材料[J];功能材料;2009年09期

9 籍遠明,張金倉;Nb_2O_5摻雜的氧化鋅陶瓷導電特性研究[J];低溫物理學報;2004年01期

10 袁方利,林元華,黃淑蘭,李晉林,季幼章;高能ZnO基復(fù)合陶瓷線性電阻的制備[J];材料研究學報;2000年05期

相關(guān)碩士學位論文 前1條

1 周勇;ZnO線性電阻的制備及其性能的研究[D];陜西科技大學;2012年

，

本文編號：2003027