反应合成原位（In—Situ）复合材料制备技术进展

在现有的复合材料制备技术中，反应合成原位复合材料制备技术具有显著的技术优势和经济优势，它的研究已成为当今复合材料领域的前沿课题。本文综合评述了这种复合材料制备亲技术。     

铁基复合材料涂层的原位反应合成

本文利用熔铸法研究了铁基复合材料的反应合成工艺和显微组织.结果表明:用液相原位反应合成法制备TiC/Fe基复合材料涂层是可行的;反应合成的TiC颗粒增强的Fe基复合材料涂层与基体没有明显的界面,涂层与基体结合状态良好;保温时间是影响TiC颗粒的大小、数量、及涂层厚度的重要因素之一.基体合金中含Ti为4%的样品保温2分钟后涂层厚度约为250μm,而保温7分钟后涂层厚度约为400μm,运用动力学计算对涂层厚度进行了理论计算,计算结果与实验结果的变化规律相似.     

原位反应复合法制备金属基复合材料的进展

综述了近年来利用原位反应复合法制备金属基复合材料的最新工艺方法，包括：ＸＤ法、ＶＬＳ法、ＳＨＳ等，讨论其组织与性能，同时还展望了原位反应复合法的发展前景。     

金属基复合材料的反应合成技术

综述了金属基复合材料的新型生产工艺－反应合成技术的现状及发展概况，重点介绍了铸造、粉末冶金、喷射沉积三种工艺过程中的反应合成技术，讨论了存在的相关问题。     

原位反应复合法制备金属基复合材料的进展

综述了近年来利用原位反应复合法制备金属基复合材料的最新工艺方法,包括：ＸＤ法、ＶＬＳ法、ＳＨＳ等。讨论其组织与性能,同时还展望了原位反应复合法的发展前景。     

原位反应铜基复合材料制备工艺

用原位反应法制备了氧化物颗粒增强铜锆基（Ａｌ２Ｏ３＋Ｃｕ２Ｏ）／Ｃｕ－Ｚｒ复合材料，并对其组织和性能进行了研究。结果表明，复合材料增强相分布均匀，尺寸细小，体积分数随反应温度和时间的不同，可以在５％￣１５％内调节，铸态显微硬度可达１０４．１。最后讨论了热处理及形变处理对复合材料组织和性能的影响。     

原位反应制备颗粒增强钛基复合材料的研究进展

原位反应制备的颗粒增强钛基复合材料中增强颗粒与基体的相容性好,复合材料高温性能稳定,成为制备高性能颗粒增强钛基复合材料的首选途径.目前,粉末冶金法、熔铸法、放热弥散法、燃烧合成法和机械合金化法都已用于原位反应制备颗粒增强钛基复合材料.综述了这些制备方法的原理、特点以及制备出的复合材料的组织和性能,指出了原位反应制备颗粒增强钛基复合材料今后的发展方向.     

原位反应在铸造法制备复合材料中的应用

铸造技术是制备金属基复合材料的一种有效手段,利用反应在铸造过程中原位生成增强相,可避免传统方法中增强相颗粒表面污染的现象,从而改善增强相颗粒与基体相的结合,并可获得细小的增强相颗粒,提高材料性能。     

原位反应复合法制备金属基复合材料的进展EI北大核心

综述了近年来利用原位反应复合法制备金属基复合材料的最新工艺方法,包括：ＸＤ法、ＶＬＳ法、ＳＨＳ等,讨论其组织与性能,同时还展望了原位反应复合法的发展前景。     

颗粒增强铝基原位复合材料

原位反应合成的颗粒增强铝基复合材料的弹性模量,比强度和高温强度均高,是航空,汽车工业上很有发展潜力的新型结构材料。综述了它的制备方法,组织结构及力学性能方面的研究进展。     

莫来石基复合材料的研究进展

由于莫来石材料的韧性、超塑性等性能较差，往往不能满足作为耐火材料、电子封装材料和光学材料等在工业中的使用要求，因而限制了它的进一步应用。本文就莫来石与堇青石、ZrO2、CNT、高硅氧玻璃、连续性纤维等改性制得莫来石基复合材料的研究进展现状进行了介绍，同时对它的发展前景进行了分析。     

原位增强镁基复合材料研究进展与原位反应体系热力学

本文综述了原位镁基复合材料制备方法的研究进展 ,并对原位镁基复合材料的可能的原位反应体系进行热力学分析     

Reaction Bonding of Three-Layer Alumina-Based Composites

Three-layer alumina-based composites with Al₂O₃-containing mullite as the outer layer and ZrO₂-containing alumina as the inner layer were fabricated by die-pressing and reaction bonding. The effects of the outer-layer compositions on the densification behavior of three-layer composites were investigated. The existence of residual stresses in the layers was verified using indentation methods. Compared with single-layer ceramics, three-layer composites exhibit an improved fracture toughness and an excellent damage resistance due to the presence of the compressive stresses in the outer layers.     

原位热压合成Nb掺杂Al2O3/TiAl复合材料

利用Al-Ti-TiO2-Nb2O5体系的放热反应,原位热压合成了Nb掺杂Al2O3/TiAl复合材料.借助DTA结合XRD探讨了Al-Ti-TiO2-Nb2O5体系的反应过程,并采用XRD、OM和SEM研究了复合材料的物相组成及显微结构.结果表明:Al熔化的同时,体系发生了Al和Nb2O5的铝热反应,生成了NbO2和Nb等中间产物,并放出了较多热量,这些热量促使Ti和Al较早化合生成TiAl3,随即引发Al和TiO2较早的还原反应,进而促使材料在较低温度下致密烧结;产物由γ-TiAl、α2-Ti3Al、Al2O3和NbAl3相构成,Al2O3颗粒分布于基体交界处,存在一定的团聚;Nb2O5的引入,对基体γ-TiAl相和α2-Ti3Al相的的分布有一定的影响,使得基体晶粒细化,较好地改善了材料的力学性能.     

紫外光辐照双原位同步合成纳米Ag/PVP复合物的结构特征

在室温下,用紫外光辐照N-乙烯基吡咯烷酮(NVP)和硝酸银(AgNO3)水溶液,双原位一步合成了纳米银/聚乙烯吡咯烷酮(PVP)复合物。透射电镜(TEM)分析表明,纳米银/PVP复合物分散性好、粒径在5 nm左右;X射线光电子能谱(XPS)表明,C=O中C1s结合能(285.61 eV)比标准C=O中C1s结合能(287.79 eV)降低了2.18 eV,N1s的结合能比标准的能谱峰位(399.88 eV)降低了0.38 eV;红外光谱(FT-IR)表明,纳米Ag/PVP羰基吸收峰,峰位从1673 cm-1变化到1661 cm-1,发生红移;XPS和FT-IR分析表明,纳米银不仅和羰基氧有相互作用,而且通过p-π共轭效应,与氮和羰基碳也发生了相互作用。     

Synthesis of C_f/TiAl_3 Composite by Infiltration-In Situ Reaction

Infiltration-in situ reaction synthesis of Cf /TiAl3 composite was investigated. The as-cast material was obtained by titanium particles, carbon fibers and pure aluminum. Titanium particles and carbon fibers were mixed and pressed to form a preform firstly, and then molten pure aluminum was pressed into the preform, subsequently, cooled rapidly. In situ reaction samples were obtained by heating the as-cast material from 600 to 1000 °C for 1 h. The microstructural evolution of in situ reaction samples was an...     

Titanium Silicide Reinforced In Situ Synthesized TiAl Composites and Their Mechanical Properties

A processing route involving in situ development of reinforcements of titanium silicides in a series of TiAl-based matrices has been attempted. The main features of this processing route are: 1) mechanical alloying of 58Ti-21Al-21Si (at%) powder mixture for 20-h to form a predominantly Ti solid solution; 2) incorporating a small quantity of mechanically alloyed powders, referred to as precursors, into Ti-Al-X (X stands for Cr, Mn, Nb, or their combination) powder mixtures that act as the matrix; and 3) hot isostatic pressing (HIPing) of the cold compacted mixture at a temperature of 1100°C for 4-h. In the present study, a series of composites based on different Ti-Al-X matrices were synthesized. After annealing at 1150°C for 4-h, their microstructures and mechanical properties were characterized by scanning electron microscopy (SEM) and compression tests at room and elevated temperatures (600°C and 800°C). The influence of alloying elements in the matrix was evaluated from the stress-strain response curves.     

不同工艺方法制备的Cu/Al2O3复合材料的组织与性能

比较了用两种不同工艺方法制备的金属氧化物增强铜基复合材料的组织和性能 ,分析了工艺方法对复合材料组织和性能的影响机理 ,提出了不同工艺条件下复合材料质量控制方法。     

Influence of Dynamic Densification on Microstructure and Properties of Reaction Synthesized TiC Ceramic

The influence of dynamic densification on the microstructure and properties of reaction synthesized bulk compacts of TiC ceramic was investigated. Self-propagating high-temperature combustion-type chemical reactions were initiated in disk-shaped green reactant compacts, cold pressed from Ti and C elemental powder mixture, by igniting with an electric match. The reaction synthesized mass was instantaneously (within zero to 20 seconds time delay) compacted by high pressure generated by explosive detonation and transmitted through a driver plate. A predictive model, based on heat flow simulation of self-propagating combustion reactions, was developed to provide a quantitative understanding of the process and subsequent cooling of the material from its adiabatic (reaction) temperature, in order to allow better control of the explosive densification step following reaction synthesis. It was determined that in addition to the dynamic-densification pressure, the time delay between reaction completion and densification, was an important variable influencing the density and microstructure (grain size) of the bulk TiC ceramic compacts. With less than the optimum time delay, the reacted and densified compact showed de-lamination and lower densities (due to effects of after-burn), and coarse-grain structure (due to slower cooling rate). Likewise, with longer than the optimum time delay, the SHS reacted product cooled below the point where densification to high density and microstructural break-down resulting in fine-grain structure could not be achieved. Under optimized conditions (time delay = 8 s, pressure = 2.5 GPa), bulk titanium-carbide ceramic compacts with densities as high as 95% of theoretical maximum density (T.M.D.) and grain size 10 m were produced. The compacts had microhardness values typically varying between 21.2 to 26.6 GPa, Young's Modulus in the range of 418 ± 20 GPa and 375 ± 14 GPa, compressive strengths between 1.0 ± 0.3 GPa and 0.9 ± 0.2 GPa, and fracture toughness values of 1.51 ± 0.3 MPam to 3.69 ± 1.0 MPam.     

微波高温加热技术进展

微波高温加热技术被认为是本世纪最有可能取代传统外部加热技术而应用于材料制备的先进技术之一.总结了近年来微波高温加热技术在理论与模拟、结构材料和功能材料方面的研究进展,并对微波高温技术在产业化方面的应用现状和发展前景进行了论述.