發(fā)布時(shí)間：2018-03-03 22:18

  本文選題：SiCN前驅(qū)體陶瓷　切入點(diǎn)：納米氧化鐵　出處：《山東大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：電磁輻射污染的治理和雷達(dá)隱身技術(shù)的發(fā)展使得吸波材料的制備和應(yīng)用成為人們研究的熱點(diǎn)。由于傳統(tǒng)型吸波材料尤其是鐵氧體和傳統(tǒng)陶瓷類吸波材料的密度相對(duì)較大,限制了其在該領(lǐng)域的進(jìn)一步發(fā)展,因此相對(duì)輕質(zhì)、導(dǎo)電性和介電性能較好的硅碳氮前驅(qū)體陶瓷在吸波材料中具有潛在的應(yīng)用價(jià)值。SiCN前驅(qū)體陶瓷材料具有優(yōu)異的導(dǎo)電性和介電性能,在此基礎(chǔ)上在SiCN前驅(qū)體陶瓷中引入鐵離子,可使其具有特別的磁性能。因此,本文以聚硅氮烷為前驅(qū)體、以過氧化二異丙苯為交聯(lián)劑,利用前驅(qū)體熱解法制備了SiCN前驅(qū)體陶瓷,分析了其在熱解過程中基本結(jié)構(gòu)的轉(zhuǎn)化和組成,研究了材料的電性能、介電性能和微波吸收性能。另外,通過添加乙酰丙酮鐵、鐵、氧化鐵和四氧化三鐵四種不同的鐵源,成功制備了SiCN(Fe)前驅(qū)體陶瓷,研究了產(chǎn)物的介電性能及磁性能,探討了鐵的加入對(duì)吸波性能的影響。通過對(duì)SiCN和SiCN(Fe)前驅(qū)體陶瓷制備及性能的研究,主要得出如下結(jié)論：分析了聚硅氮烷前驅(qū)體的交聯(lián)熱解過程,紅外光譜分析發(fā)現(xiàn)在800℃時(shí),樣品已基本陶瓷化,且熱重分析表明其陶瓷化程度在75%左右；光電子能譜分析結(jié)果表明,熱解產(chǎn)物以Si、C、N的成鍵和游離C的形式存在,N有部分流失；XRD結(jié)果表明：該SiCN前驅(qū)體陶瓷在900℃-1350℃熱解時(shí)具有無定型結(jié)構(gòu)；微觀結(jié)構(gòu)分析表明隨著熱解溫度的升高,樣品的均一性提高,氣孔率降低,1400℃及以上溫度熱處理時(shí),SiCN前驅(qū)體陶瓷會(huì)由非晶相結(jié)構(gòu)向晶體結(jié)構(gòu)轉(zhuǎn)變。研究了熱解溫度對(duì)SiCN前驅(qū)體陶瓷電性能及介電性能的影響,發(fā)現(xiàn)在不同溫度處理的SiCN前驅(qū)體陶瓷的I-V關(guān)系基本為直線,且隨著處理溫度的增加(1000℃-1450℃),前驅(qū)體SiCN陶瓷的電阻率降低,電導(dǎo)率升高,介電常數(shù)升高,材料的介電性能有明顯提高；同時(shí)探討了樣品厚度對(duì)SiCN前驅(qū)體陶瓷的介電性能的影響,結(jié)果表明：當(dāng)樣品厚度最大為4mm時(shí),材料的介電性能最優(yōu),且當(dāng)頻率達(dá)到12.7GHz時(shí),其介電損耗達(dá)到最大為3.1。研究了甲基丙烯酸對(duì)SiCN前驅(qū)體陶瓷的結(jié)構(gòu)、含碳量及介電性能和吸波性能的影響。結(jié)果表明：當(dāng)添加6wt%的甲基丙烯酸時(shí)樣品的含碳量明顯增加,介電常數(shù)明顯增大,在12.7GHz處,樣品6-MA的介質(zhì)損耗達(dá)到最大為0.75,反射率達(dá)到-4.8dB,電磁衰減系數(shù)為240,該材料具有一定的吸波性能。將乙酰丙酮鐵、鐵、氧化鐵和四氧化三鐵四種鐵源分別與聚硅氮烷復(fù)合制備了SiCN(Fe)前驅(qū)體陶瓷,研究了各個(gè)樣品的結(jié)構(gòu)、相組成及微波吸收性能。XRD結(jié)果表明,樣品中均出現(xiàn)α-Fe和C兩種晶體；從電磁性能分析可知,鐵源的加入使得材料的介電常數(shù)和介電損耗明顯增加,與其他鐵源相比,Fe304的加入對(duì)材料的介電損耗和磁損耗的影響較大,且10GHz左右共振峰的出現(xiàn)使得兩種損耗均達(dá)到最大值,其介電損耗值為2.1,磁損耗角正切值為0.5,這與極化機(jī)制的退出和轉(zhuǎn)變有關(guān)。由于介電共振峰和磁共振峰的存在,在10GHz處加入Fe304的SiCN(Fe)前驅(qū)體陶瓷的反射率低于其它樣品,為-4.7dB,其電磁衰減系數(shù)達(dá)到最大,為800。探討了納米氧化鐵的加入量(6wt%,12wt%,15wt%,18wt%)對(duì)SiCN(Fe)前驅(qū)體陶瓷吸波性能的影響。結(jié)果表明當(dāng)樣品中加入18wt%的納米氧化鐵時(shí),在10GHz處,材料的反射率R降到最低,電磁衰減系數(shù)“的值達(dá)到最大,其值分別為-11dB和325,吸波性能較好,能夠滿足微波吸收的要求。本論文制備的SiCN前驅(qū)體陶瓷和SiCN(Fe)前驅(qū)體陶瓷可作為微波吸收材料,具有著良好的潛在應(yīng)用前景。
[Abstract]:The development of stealth technology, electromagnetic radiation pollution governance and the radar absorbing material preparation and application become the research hotspot. Because the traditional absorbing materials especially ferrite and traditional ceramic absorbing wave material density is relatively large, the limit in the field of further development, so relatively light, the conductivity and dielectric properties of silicon carbonitride ceramic precursor in microwave absorbing material has the application value of.SiCN precursor ceramic material potential has excellent conductivity and dielectric properties, on the basis of the precursor of SiCN ceramic by iron ion, which can have their special magnetic properties. Therefore in this paper, polysilazane precursor with two peroxide cumene as crosslinking agent, the precursor of SiCN ceramic prepared by precursor pyrolysis method, analyzes the basic structure and transformation in the pyrolysis process, the material is studied. Electrical properties, dielectric properties and microwave absorption power. In addition, by adding acetylacetone iron, iron, iron oxide and iron oxide in four different iron sources, SiCN was successfully prepared (Fe) precursors of ceramics, dielectric properties and magnetic properties of the product, discusses the iron addition effect on absorbing properties. Based on the SiCN and SiCN (Fe) of the ceramic precursor preparation and properties, the main conclusions are as follows: the analysis of the process of crosslinking pyrolysis of polysilazane precursor, infrared spectroscopy analysis showed that at 800 DEG C, the sample has been basically ceramic, and thermogravimetric analysis showed that the degree in ceramics about 75%; photoelectron spectroscopy. The results showed that the pyrolysis products are mainly Si, C, C are bonded and free form of N, N is part of the loss; XRD results showed that the precursor of SiCN ceramics at 900 DEG -1350 DEG pyrolysis with amorphous structure; microstructure analysis shows that with the The increase of pyrolysis temperature, homogeneity of the samples increased, the porosity decreased and the temperature above 1400 DEG C and heat treatment, SiCN ceramic precursor from amorphous phase structure to change the crystal structure. The effect of pyrolysis temperature on the precursor of SiCN ceramic dielectric properties and dielectric properties of SiCN ceramic precursor, found in different the temperature of processing I-V relationship as a straight line, and with the increase of treatment temperature (1000 DEG -1450 DEG), resistivity precursor of SiCN ceramic decreased, the conductivity increased, higher dielectric constant, dielectric properties of materials are improved obviously; and discuss the influence of sample thickness on the dielectric properties of SiCN ceramic precursor the results show that when the thickness of the sample was 4mm, the optimal dielectric properties of materials, and when the frequency reaches 12.7GHz, the dielectric loss reached a maximum of 3.1. to study the structure of methacrylic acid on SiCN ceramic precursor, carbon Effect of amount and dielectric properties and microwave absorbing properties. The results show that when the carbon content of methacrylic acid 6wt% added sample was significantly increased, the dielectric constant was increased at 12.7GHz, the dielectric loss of the sample 6-MA reached a maximum of 0.75, the reflectivity of -4.8dB, electromagnetic attenuation coefficient is 240, the material has the microwave absorbing properties. The ferric acetylacetonate, iron oxide and iron oxide, four iron source and polysilazane compound was prepared by SiCN (Fe) ceramic precursor, studied the structure of each sample, phase composition and microwave absorption properties of.XRD showed that the alpha -Fe and C two kinds of crystal appeared in the sample; from the analysis of the electromagnetic properties of the iron source due to the dielectric constant and the dielectric loss was obviously increased, compared with other iron sources, effects of Fe304 addition on the dielectric loss and magnetic loss is large, and the resonance peak is about 10GHz Now the two losses reached the maximum, the dielectric loss value is 2.1, the magnetic loss tangent was 0.5, and the polarization mechanism of exit and transformation. Because the dielectric resonance and magnetic resonance peak, adding Fe304 at 10GHz SiCN (Fe) ceramic precursor reflectivity below the other sample is -4.7dB, the electromagnetic attenuation coefficient reached the maximum amount of iron oxide nanoparticles was 800. (6wt%, 12wt%, 15wt%, 18wt%) of SiCN (Fe) precursor ceramic absorbing properties was studied. The results show that when adding iron oxide nano 18wt% samples, at 10GHz, reflectivity of R materials to a minimum, "the electromagnetic attenuation coefficient reaches the maximum value, the value of -11dB and 325 respectively, the absorbing performance is good, can satisfy the requirements of microwave absorption. This paper prepared precursor of SiCN ceramic and SiCN ceramic precursor (Fe) can be used as microwave absorbing materials, has a good Potential application prospects.

【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TQ174.1

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本文編號(hào)：1562939