还原合成技术在无机材料合成中的应用及进展

碳热还原、镁热还原、铝热还原合成技术广泛应用于无机材料的合成中,应用它们可以制备碳化物、硼化物、氮化物、金属单质及复合材料等多种新型材料。自蔓延高温还原合成技术(SHS Reduction)是一种工艺简单、节能、高效的制备高技术材料的先进方法,主要有镁热还原SHS技术和铝热还原SHS技术。本文阐述了传统还原合成工艺及自蔓延高温还原合成技术在无机材料合成中的应用及进展。     

自蔓延高温合成技术的发展与应用

自蔓延高温合成技术是20世纪后期诞生的一门新兴的前沿科学，在粉体合成及陶瓷涂层内衬的制备等方面充分显示其优越性。本文对自蔓延高温合成技术的概念、国内外基本情况进行了阐述，同时简要介绍了自蔓延高温合成的燃烧理论．对利用自蔓延合成技术进行粉体合成及陶瓷内衬钢管的应用研究等作了较为详尽的说明。     

陶瓷材料新术语诠释(十五)

自蔓延高温合成是近30年发展起来的制取高温、难熔、耐磨等类材料及制品的新技术。该技术是利用外加热源将具有高放热效应的反应物点燃,通过反应放出的热量形成自我蔓延的燃烧波,使反应持续维持。燃烧过程中产生高温(可达1500～4000℃),从而合成新的材料。这样合成的产物一般是松散的粉末,可以通过加压     

陶瓷色料的自蔓延高温合成新工艺

本文综述了陶瓷色料自蔓延高温合成新工艺的原理、优点及前景 ,同时论述了色料自蔓延高温合成的影响因素。     

自蔓延高温合成Ti3AlC2 和Ti2AlC及其反应机理研究

以Ti,Al和C的粉体混合物为原料，在纯氩气气氛，25MPa压力，1600℃保温4h条件下，自蔓延高温合成了Ti3AlC2和Ti2AlCT，利用X射线衍射分析（XRD）和扫描电镜（SEM）等手段对反应产物进行了研究，提出了自蔓延高温合成Ti3AlC2和Ti2AlC应具备的条件，并探讨了Ti，Al和C自蔓延高温合成Ti3AlC2和Ti2AlC的反应机理，结果表明，Ti3AlC2和Ti2AlC能够由Ti,Al和C元素经高温自蔓延合成反应来制备，其制备的必要条件是需要极快的加热速率以防止铝熔化并且改变钛的转移路线，Ti3AlC和Ti2AlC综合了金属材料和陶瓷材料的优点，成功的应用自蔓延高温方法合成Ti2AlC2和TiAlC必将成为该类材料纯块体的合成和制备提供好的原料，从而这类材料的实际应用将起到极大的推动作用。     

超细TiC粉体的制备方法及应用研究进展

结合近年TiC材料的研究进展,对超细TiC粉体的制备方法进行了综述,介绍了还原法、自蔓延高温合成法（SHS）、机械合金化法、微波法、气相反应合成法及等离子体法,简述了TiC在增强颗粒、航空航天材料及涂层材料方面的应用。     

多孔陶瓷制备技术的进展

多孔陶瓷是一种含有较多孔隙的无机功能材料,在化工、冶金、运输等领域有着广泛的应用前景.对多孔陶瓷的制备技术及最新研究进展进行了详细的综述,报道了一种在自蔓延高温合成法和发泡法基础上创新的制备方法--自蔓延高温合成喷射法,并对未来研究方向进行了展望,认为今后对多孔陶瓷制备技术的研究将沿着对现有技术进行改进及结合其他种类材料的制备技术进行创新等两个方向开展.     

自蔓延高温合成NiAl基金刚石工具材料的热力学研究

计算了Ni-Al体系及Ni-Al-金刚石体系自蔓延高温合成NiAl金属间化合物的绝热温度,运用物质自由能函数理论,对主要反应进行了热力学计算,结合相图预测了自蔓延高温合成产物,并用自蔓延高温合成实验结果与预测结果进行对比,分析了自蔓延高温合成NiAl金属间化合物的物相生成过程。结果表明:4Ni-2Al反应的驱动力比Ni-Al体系的大,4Ni-2Al体系绝热温度为1816 K,可实现燃烧波自维持,根据相图预测产物是NiAl和Ni_(3)Al,确定最佳的Ni-Al体系配比为4Ni-2Al。4Ni-2Ali-10%(质量分数)金刚石体系与4Ni-2Al-15%(质量分数)金刚石体系的绝热温度分别为1709 K和1655 K,均可实现燃烧波自维持,自蔓延高温合成产物均为NiAl、Ni_(3)Al及部分Ni。热力学分析结果与XRD、FESEM及EDS能谱分析结果是吻合的。     

合成工艺对氮化硅铁物相和结构的影响

以硅铁合金(FeSi75)为原料,分别采用闪速燃烧合成工艺和自蔓延高温合成工艺制备氮化硅铁样品,利用X射线衍射仪和扫描电镜对样品进行了表征,探讨了合成工艺对氮化硅铁物相和显微结构的影响。采用闪速燃烧工艺合成的氮化硅铁相组成为β-Si3N4,α-Si3N4,Fe3Si和少量SiO2;而采用自蔓延高温合成的氮化硅铁由β-Si3N4,α-Si3N4,Fe3Si和Si2N2O组成。闪速燃烧合成的氮化硅铁样品中存在大量长径比较高的柱状氮化硅晶体,Fe3Si位于柱状结晶所包裹材料的内部;自蔓延高温合成的氮化硅铁显微结构为致密的氮化硅块体,在块体表面覆盖有氧氮化硅膜,块体的间隙存在晶形细小的氮化硅晶体,含铁组分镶嵌在致密的块体中。闪速燃烧合成的氮化硅铁结构疏松,活性较强;自蔓延高温合成的氮化硅铁结构致密,性质稳定。     

自蔓延高温合成的发展前景

介绍了自蔓延高温合成的现状和发展方向,分别从理论和合成技术上对自蔓延高温合成前景进行分析和概述,燃烧过程的动力学研究将成为今后理论研究的热点,在生产技术上电场、磁场、重力对SHS工艺及制品的性能会产生影响。     

自蔓延高温合成陶瓷材料

本文系统地阐述了自蔓延温合成（ＳＨＳ）陶瓷材料的概念，从动力学、热力学、以及燃烧学角度讨论了ＳＨＳ法的理论与应用。     

Effect of batch pelletizing on a course of SHS reactions: An overview

Such a simple technological trick as pelletizing (granulating) green powder mixtures (popular in conventional powder technology) has seldom been used in SHS technology. We have demonstrated that pelletizing green powder mixtures can markedly affect the parameters of various SHS reactions (SHS in a mode of infiltration-mediated combustion, SHS with a reduction stage, combustion of thermit mixtures, SHS in aluminum melt) and properties of their products.     

Mathematical modelling of structure formation during combustion synthesis of advanced materials

The synthesis of advanced materials by a wave of heterogeneous combustion propagating through a charge mixture, or the so-called self-propagating high-temperature synthesis (SHS) has many potential advantages over conventional techniques of synthesis. Because of high heating rates, steep temperature and concentration gradients, and fast accomplishment of reactions, the mechanisms of physical, chemical and structural transformations in the SHS wave are intricate and often not known. Further understanding of interaction mechanisms in SHS waves, relating the process parameters to structure and properties of the target material, and the application of SHS to producing final articles necessitates developing mathematical models for SHS-related phenomena.Various aspects of mathematical modelling of SHS are discussed in this paper. They include the analysis of novel factors influencing the structure formation, viz. the heating-to-reaction and mass transfer-to-reaction time ratios, autocatalysis and intrinsic stochasticity, which are unnoticed in traditional synthesis methods. The application of chemical thermodynamics and combustion theory to modelling SHS processes is outlined. Novel mathematical models are developed for SHS on condensed systems, which involve stochastic effects and autocatalysis. New models for solid-gas systems are worked out, which include the reaction kinetics and mass transfer of a gaseous reactant and permit predicting the structure formation pattern in the SHS wave. Application of mathematical modelling to producing porous final articles by means of SHS is discussed.     

SHS结合密实化技术制备材料进展

SHS结合密实化技术可以一步完成材料的合成与致密化过程,这是该领域研究的最新方向.本文介绍了国内外正在研究的几种典型的SHS结合密实化技术,对它们的优劣进行了分析,认为SHS/QP方法是一种有希望的材料制备技术.     

SHS in the UK: Past, present, and future directions

The United Kingdom has played a small but significant role in the development of SHS. Parkin and Kuznetsov have studied the formation of complex oxides in external fields. Wood and Christanthou have studied the formation of intermetallic compounds and refractory materials by SHS. Perry, Thompson, and Green have made contributions to the synthesis of materials by solution phase auto-combustion reactions. The UK has also made contributions to the theory of SHS and the monitoring of SHS reactions by time resolved X-ray, neutron, and thermal imaging studies. The UK has been at the forefront in the development of a sub-class of SHS reactions termed solid state metathesis. Presented at the International Conference on Historical Aspects of SHS in Different Countries, October 22–27, 2007, Chernogolovka, Moscow, Russia.     

气相传输SHS合成Ti5Si3的过程参数与产物结构的研究

气相传输自蔓延高温合成技术是通过引入气相传输助剂来改变ＳＨＳ过程的一种方法。ＧＴＡ的引入对ＳＨＳ过程参数，产物结构等产生显著的影响。本研究采用气相传输自蔓延高温合成法制备了Ｔｉ５Ｓｉ３，并着重研究了ＧＴＡ对热爆和自蔓延燃烧过程参数的影响，运用ＸＲＤ和ＳＥＭ对产物的组成与微观结构进行了分析。     

自蔓延高温合成细晶六硼化钙陶瓷粉末(英文)

基于Mg–B2O3–CaO原料体系,采用自蔓延高温合成(self-propagating high-temperature synthesis,SHS)和后期酸处理工艺,制备出高纯度、均匀分布、小粒径的立方晶型细晶六硼化钙粉末。分析了Mg–B2O3–CaO自蔓延高温反应体系的燃烧产物成分及反应机理,测量了不同SHS反应物原始坯体成型压力的燃烧温度曲线,探讨了不同镁掺量和不同气氛对燃烧产物成分和形貌的影响。研究了原始坯体成型压力与最终CaB6产物粒径的关系。结果表明:采用氩气保护能抑制镁挥发;合适的原始坯体压力有利于合成分布均匀的细晶CaB6粉末。     

Advanced methods for SHS of powders developed in Krakow

History of the involvement of our laboratory in SHS research and characterization of the main ideas of this research focused on developing advanced methods of powder synthesis for macro-and nanotechnologies with the use of SHS are overviewed. By the low cost of installations and simplicity of the process, SHS over-shadows most advanced methods of synthesis and has the potential to be developed into large scale production. The mechanism of SHS reactions often differs from that of reactions at lower temperatures and due to this the particulate SHS products may have properties valuable for some specific applications. A more detailed illustration of these problems is presented for SHS-derived powders of compounds, such as SiC and Ti₃SiC₂, which have unique properties and applications. Presented at the International Conference on Historical Aspects of SHS in Different Countries, October 22–27, 2007, Chernogolovka, Moscow, Russia.     

SHS转炉补炉料的物相组成及显微结构特征

利用自蔓延高温合成(SHS)原理,选择工业铝粉作为发热剂,菱镁矿为供氧剂,通过铝热反应,研制出了一种以镁砂为骨料,以镁铝尖晶石和炭质材料作为结合相的新型SHS转炉补炉料.对不同环境温度下补炉料的物相组成及显微结构进行了研究,并对合成尖晶石的固相反应原理及SHS产物相的烧结机制进行了探讨.结果表明补炉料中颗粒状的骨料方镁石与SHS反应产物尖晶石、非晶质碳、少量刚玉相和硅酸盐玻璃相共同构成含有气孔的交织结构,形成尖晶石、碳桥和陶瓷相与方镁石骨料的多重结合;SHS反应过程分碳酸盐矿物的分解反应、铝热氧化还原反应(即SHS反应)和合成尖晶石的固相烧结反应三步进行,其烧结受扩散机理控制.