共掺杂SiC微波吸收剂的制备和性能研究

发布时间：2018-04-05 18:53

本文选题：碳化硅　切入点：吸收剂　出处：《西安电子科技大学》2015年硕士论文

【摘要】：吸波材料作为隐身技术的重要组成部分,其性能取决于吸收剂对电磁波的损耗能力。对于武器装备高温部件的隐身以及高温下的电磁波屏蔽等,都需要能承受高温的微波吸收剂。SiC作为性能优异的耐高温材料,在高温吸波材料领域有着广泛的应用前景。本文采用燃烧合成法制备B/Al、B/N和Al/N共掺杂的SiC粉体吸收剂,通过X-射线衍射分析、X射线光电子分析、扫描电子显微镜和介电性能测试等,系统的研究了共掺杂SiC粉体吸收剂制备、结构和性能之间的关系,深入讨论了共掺杂对SiC吸收剂微波介电性能的影响及其相关机理。以Si粉和炭黑为原料,B粉为掺杂剂,PTFE为化学活性添加剂,制备B掺杂SiC粉体吸收剂。研究了不同B掺杂量对其性能的影响。结果表明:所合成纳米粉体的介电常数实部ε′、虚部ε″和损耗角正切tanδ值均随着B掺杂量的增加而降低。同时,采用Al粉为掺杂剂合成Al掺杂SiC纳米粉体,发现当Al的掺杂量增加至10%和15%时,合成产物中出现的Al2O3杂质相。当Al掺杂量为10%时,样品的ε′、ε″和tanδ值最高,分别为ε′=5.2~5.5、ε″=1.5~1.7、tanδ=0.29~0.31。以B粉和Al粉为掺杂剂,制备B、Al共掺杂的SiC粉体吸收剂。结果表明:当B掺杂量为5%,Al的掺杂量分别为5%、10%和15%时所合成样品的ε′、ε″和tanδ值均小于未掺杂Al的SiC样品;当Al掺杂量为10%时,所制备样品的ε′、ε″和tanδ值最大,分别为ε′=3.5~3.6,ε″=0.375~0.4和tanδ=0.09~0.1。当Al掺杂量为5%,B的掺杂量分别为5%、10%和15%时,合成样品的ε′、ε″和tanδ值均随着B掺杂量的增加而降低。以NH4Cl为氮化剂,B粉为掺杂剂,采用燃烧合成法,制备B、N共掺SiC粉体吸收剂。发现不同N掺杂量时,均制备了较纯的B、N共掺杂β-SiC纳米粉体。微波介电性能研究表明,合成样品的ε′、ε″和tanδ值均随着N掺杂量的增加而减小。又研究了不同B掺杂量的影响。同样地,合成样品的ε′、ε″和tanδ值均随着B掺杂量的增加而减小。以Si3N4为氮化剂、B粉为掺杂剂,采用燃烧合成法,制备B、N共掺杂SiC粉体吸收剂。XPS分析证明了B、N成功地掺杂进入SiC晶格。介电性能结果表明,不同N掺杂量合成样品的ε′、ε″和tanδ值均随着N掺杂量的增加先减少后增加。当B掺杂量为5%、N掺杂量为15%时,共掺杂样品的ε′、ε″和tanδ值高于未掺杂样品。但是,不同B掺杂量时,共掺杂样品的ε′、ε″和tanδ值均小于未掺杂SiC样品,其随着B掺杂量的增加先减少后增加。以Al粉为掺杂剂,Si3N4为氮化剂,采用燃烧合成法,制备Al、N共掺杂的SiC粉体吸收剂。结果表明:当Al的掺杂量为5%,不同N掺杂量时,发现掺杂样品的介电常数实部ε′、虚部ε″和tanδ均小于未掺杂样品,且随着N含量的增加而减少。对N掺杂量为5%,不同Al掺杂量的影响研究表明,当Al的掺杂量为10%、15%时,合成产物中出现了Al2O3的杂质峰,样品的介电常数实部ε′、虚部ε″和tanδ整体上随着Al掺杂量的增加逐渐减小。
[Abstract]:As an important part of stealthy technology, the performance of absorbing materials depends on the loss of electromagnetic wave caused by absorbent.For the stealth of high temperature parts of weapon equipment and electromagnetic wave shielding at high temperature, microwave absorbent. Sic, which can withstand high temperature, is required as a high temperature resistant material with excellent performance. It has a wide application prospect in the field of high temperature absorbing materials.In this paper, SiC powder absorbent co-doped with B / AlN / B / N and Al/N was prepared by combustion synthesis method. X-ray photoelectron analysis, scanning electron microscope and dielectric property test were used to study the preparation of co-doped SiC powder absorbent.The effect of co-doping on microwave dielectric properties of SiC absorbers and its related mechanism are discussed.B doped SiC powder absorbent was prepared by using Si powder and carbon black as raw material and B powder as dopant.The effects of different B doping contents on the properties were studied.The results show that the dielectric constant 蔚, imaginary 蔚 "and loss angle tangent tan 未 decrease with the increase of B doping content.At the same time, the Al doped SiC nano-powders were synthesized with Al powder as dopant. It was found that the Al2O3 impurity phase appeared in the synthesized product when the doping amount of Al was increased to 10% and 15%.When Al doping amount is 10, the samples have the highest 蔚 ~ (+), 蔚 "and tan 未 values, which are 蔚 ~ (2 +) ~ (5. 2) ~ (5.5), 蔚" ~ (1.5) ~ (1.7) tan 未 ~ (0.29) ~ (0.31) ~ (-1), respectively.Using B powder and Al powder as dopant, the SiC powder absorbent doped with B and Al was prepared.The results show that the 蔚, 蔚 "and tan 未 values of the synthesized samples are lower than those of the undoped SiC samples when the B doping amount is 5% and 15%, respectively, and the 蔚, 蔚" and tan 未 values of the prepared samples are the highest when the Al doping amount is 10%.The results are as follows: 蔚 ~ (3. 5) ~ (3. 6), 蔚 "" 0.375 ~ (0. 4) and tan 未 ~ (0.09) ~ (0.1).When the doping amount of Al is 5% and 15% respectively, the 蔚, 蔚 "and tan 未 values of the synthesized samples decrease with the increase of B doping amount.Using NH4Cl as nitridation agent and B powder as dopant, Bon N co-doped SiC powder absorbent was prepared by combustion synthesis method.It was found that pure 尾 -SiC nano-powders were prepared with different amount of N doping.The microwave dielectric properties of the synthesized samples show that the 蔚 ~ +, 蔚 "and tan 未 values decrease with the increase of N doping content.The influence of different B dopants was also studied.Similarly, the 蔚 O, 蔚 "and tan 未 values of the synthesized samples decrease with the increase of B doping content.The results of dielectric properties show that the 蔚, 蔚 "and tan 未 values of the samples with different N doping amount decrease first and then increase with the increase of N doping content.When B doping amount is 5 and N doping amount is 15, the 蔚, 蔚 "and tan 未 values of co-doped samples are higher than that of undoped samples.However, the values of 蔚, 蔚 "and tan 未 of co-doped samples are lower than that of undoped SiC samples with different B doping contents, and decrease first and then increase with the increase of B doping content.AlN co-doped SiC powder absorbent was prepared by combustion synthesis with Al powder as dopant and Si _ 3N _ 4 as nitridation agent.The results show that when the doping amount of Al is 5 and the doping amount of N is different, it is found that the dielectric constant 蔚, imaginary 蔚 "and tan 未 of doped samples are smaller than those of undoped samples, and decrease with the increase of N content.The effect of different Al doping amount on N doping is 5. The results show that when the doping amount of Al is 10 and 15, the impurity peak of Al2O3 appears in the synthesized product, and the real part of the dielectric constant of the sample is 蔚.As a whole, the imaginary 蔚 "and tan 未 decrease with the increase of Al doping amount.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB34

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