Si3N4／Si3N4陶瓷连接的研究进展

本文综述了Ｓｉ３Ｎ４／Ｓｉ３Ｎ４陶瓷连接的研究现状，论述不同连接工艺对接头强度的影响。     

Si3N4／SiCp复相陶瓷材料的研究进展

概述了ＳｉＣ颗粒弥散强化Ｓｉ３Ｎ４陶瓷的研究近况,着重讨论了ＳｉＣ粒子的数量和尺寸对Ｓｉ３Ｎ４／ＳｉＣｐ复相陶瓷材料显微结构和力学性能的影响,并简要介绍了Ｓｉ３Ｎ４／ＳｉＣｐ复相陶瓷材料的烧结机理和ＳｉＣｐ的掺入对材料可烧结性的影响。     

β-Si3N4及添加β-Si3N4的α-Si3N4的气氛加压烧结

介绍了β－Ｓｉ３Ｎ４及添加β－Ｓｉ３Ｎ４的α－Ｓｉ３Ｎ４的气氛加压烧结,β－Ｓｉ３Ｎ４在ＧＰＳ中具有低于α－Ｓｉ３Ｎ４的烧结活性而且陶瓷显微结构更容易调节,由ＧＰＳβ－Ｓｉ３Ｎ４制备的陶瓷材料晶粒比较均匀,具有较高的力学性能,尤其是高的韦泊模数,添加于α－Ｓｉ３Ｎ４中的β－Ｓｉ３Ｎ４对陶瓷材料显微结构具有明显的调控作用。     

Si3N4基陶瓷热腐蚀研究现状及进展

本文针对Ｓｉ３Ｎ４基陶瓷材料作为高温结构材料使用的不同环境，首先讨论了Ｓｉ３Ｎ４陶瓷在高温下氧化，继而讨论了Ｓｉ３Ｎ４陶瓷在熔融盐（钠盐或钾盐）中的腐蚀研究现状。本文最后指出了腐蚀研究中存在的问题，提出了今后应进行了研究方向。     

Si3N4／SiCp复相陶瓷研究现状及进展

详细介绍了ＳｉＮ４／ＳｉＣｐ复相陶瓷的研究现状，着重论述了Ｓｉ３Ｎ４／ＳｉＣｐ纳米复相陶瓷的制备工艺及发展趋势。     

Si3N4陶瓷材料的氧化行为及其抗氧化研究

研究了Ｓｉ３Ｎ４陶瓷材料的氧化行为,同时探讨了通过表面处理使Ｓｉ３Ｎ４陶瓷材料表面形成一层Ｓｉ２Ｎ２Ｏ对其抗氧化性能的影响。实验结果表明,Ｓｉ３Ｎ４陶瓷材料在空气中的氧化行为服从抛物线规律。另外,用Ｘ射线衍射分析（ＸＲＤ）和Ｘ光电子能谱（ＸＰＳ）分析验证了Ｓｉ２Ｎ２Ｏ层的存在。由于形成了Ｓｉ２Ｎ２Ｏ层,Ｓi３Ｎ４陶瓷材 在１３００℃下氧化１００h后,氧化增重从原来的０．４２ｍｇ／ｃｍ＾２降低到０．２     

Si3N4／SiC纳米复相陶瓷研究进展

本文综述了Ｓｉ３Ｎ４／ＳｉＣ纳米复相陶瓷的研究进展,较详细地介绍了纳米粉体的制备工艺及热处理研究、复相陶瓷的制备工艺、力学性能、微观结构及增韧强化机理。     

Si3N4结合的SiC耐火材料的机械强度

本文研究了不同Ｓｉ３Ｎ４含量的Ｓｉ３Ｎ４－ＳｉＣ复合材料的微观结构对该材料的机械强度的影响，将ＳｉＣ颗粒与不同含量的Ｓｉ粉（Ｓｉ含量的质量百分数分别为１５，２０，２５和４０）的混合物压制成试条，在Ｎ２气氛下煅烧使Ｓｉ转化成Ｓｉ３Ｎ４，该复体积密度随着氮化反应中Ｓｉ３Ｎ４含量的增加而增加，复合材料的抗折强度与体积密度未呈现有线性依赖关系，但该性能与材料中大气孔率和微气孔率的变化有密切关系。     

利用Ti／Ni共晶反应连接Si3N4／Ni的连接强度

本文用Ｔｉ箔在１３２３Ｋ直接进行Ｓｉ３Ｎ４／Ｎｉ的真空连接。结果表明,通过Ｎｉ、Ｔｉ之间的相互扩散形成的液体合金与Ｓｉ３Ｎ４发生界面反应,形成Ｓｉ３Ｎ４／ＴｉＮ／Ｔｉ５Ｓｉ４＋Ｎｉ３Ｓｉ（混合层）的接合界面,ＴｉＮ层和混合层的生长均 物线规律生长因子分别为１．３×１０＾－８ｍｓ＾－１／２和７．４×１０６－８ｍｓ＾１／２。接头弯曲强度随连接时间的增加,即Ｓｉ３Ｎ４／ＴｉＮ界面的连续和致密化而显著提高     

Si3N4粉末在空气中的氧化反应方式

本文以ＳｉＮ４粉末作为研究对象，首次采用化学分析的方法发现在Ｓｉ３Ｎ４的氧化过程中有ＮＯ气体生成，打破了传统的Ｓｉ３Ｎ４氧化生成的气态产物只有Ｎ２的看法。采用Ｈ２ＳＯ４＋ＨＮＯ３的混合液作为ＮＯ的吸收液，以ＫＭｎＯ４作为氧化剂，用氧化－－还原滴定法对ＮＯ进行检测。并利用ＸＲＤ和ＸＰＳ分析了Ｓｉ３Ｎ４粉末表面氧化层的组成。根据实验结果和热力学分析，探讨了Ｓｉ３Ｎ４粉末在空气中的氧化反应方式。     

Unconventional joining techniques of ceramics by rapid heat sources: A review

Ceramics are difficult to machine into complex shapes due to their high hardness and brittleness. In practical applications, ceramics often need to be jointed to themselves or metals. Traditional joining processes such as brazing and diffusion bonding are inefficient and costly, greatly limiting their practical applications. To solve the problems, current work explores the characteristics, applications, and prospects of unconventional and efficient joining techniques of ceramics. The joining processes are classified by heat sources, including resistance brazing, flash joining, laser welding/brazing, arc welding, and microwave joining. Additionally, current work provides solutions for resistance brazing of non-conductive ceramics, microwave joining of low dielectric loss ceramics, and laser welding of transparent ceramics. Among these techniques, USP laser welding is one of the most promising rapid joining techniques due to its ability to effectively reduce heat affected zone and residual stress.     

Ceramics/metals joining under the influence of electric field: A review

Joining ceramics with ceramics and/or metals is of immense importance to widen the application horizons of ceramics and metals. Solid-state joining is restrained by the high joining temperature and long joining time, both of which can be reduced by liquid-state joining. However, the operating temperature of different ceramic-based components is low because of the low melting temperature of the filler. In order to rapidly join ceramic-based materials at low temperatures, various joining techniques utilizing the effect of an electric field (E-field) have been developed. These methods are generally classified into four categories, i.e., spark plasma sintering joining, low E-field assisted joining, anodic bonding and flash joining, according to the value of applied E-field and the types of materials to be joined, resulting in different joining mechanisms and joint performances. These methods are reviewed from the viewpoint of material types that can be joined and mechanisms.     

Joining partially-sintered alumina ceramics using a mixture slurry of alumina sol and suspension

The joining of advanced ceramics allows the manufacture of components with a range of complex shapes that cannot be achieved in a cost-effective manner using existing techniques, i.e. green state shaping and/or machining. A new technique for joining partially-sintered alumina ceramics was developed by simply using a mixed slurry of Al₂O₃ sol and suspension. The interlayer of the joints had the same composition as the parent bodies, and the mechanical and chemical properties of the joint were comparable to those of the bulk material. This process can be applied to the joining of a variety of advanced ceramics.     

非氧化物陶瓷连接技术的进展

非氧化物陶瓷作为高温结构材料其应用前景非常广阔，但非氧化物陶瓷自身及其与金属的连接问题制约了它的工程使用，与氧化物陶瓷连接相比，非氧化物陶瓷的连接目前基本上处于基础性研究和实验室研究阶段，本文概述了这些年用于非氧化物陶瓷连接的几种方法及其工艺特点，其中包括：活性金属钎焊法，热压扩散连接法，过渡液相连接法，反应成形连接法，自蔓延高温合成（SHS）焊接法，热压反应烧结连接法和直接敷铜（DBC）法。     

先进陶瓷连接的新技术-坯体连接技术

先进陶瓷的连接技术在陶瓷研究中引入注目 ,因为它提供了一种获得以现有的技术不能制造或是制造不经济的复杂形状的陶瓷构件的方法。而今一种新的陶瓷连接技术—坯体连接出现了 ,它以简单的工艺、高效的性价比 ,赢得了世人的注目。运用新的料浆工艺和成型技术 ,坯体连接技术从传统陶瓷领域走向了先进陶瓷的领域 ,成为高性能复杂形状陶瓷构件的有效生产方法之一。     

Pressure-less joining of alumina ceramics by the reaction-bonded aluminum oxide (RBAO) method

The present work demonstrates a pressure-less and reliable joining technique for alumina ceramics through a reaction-bonded aluminum oxide (RBAO) method. Effective joining relies on the RBAO mechanism, in which Al particles are converted to alumina through oxidation and bond with alumina particles from the parts to be joined upon sintering. Alumina ceramics in a green state were successfully joined with the use of an Al/Al₂O₃ powder mixture as an interlayer. The oxidation behavior of the Al particles was confirmed by thermogravimetry and X-ray diffraction analyses. Joining was performed in ambient air at 1650 °C for 2 h without applying any external pressure. Microstructural observations at the joining interfaces indicated a compact joining. The joining strengths were assessed by determining the biaxial strengths at room temperature, and the joined samples exhibited no fractures at the joining interfaces. Moreover, the joints had a strength of almost 100 % when compared with those of the parent alumina ceramics.     

Combustion joining of refractory materials

This paper overviews heterogeneous exothermic reactive systems as they apply to the joining of materials. Techniques that are investigated fall under two general schemes: so-called Volume Combustion Synthesis (VCS) and Self-Propagating High-Temperature Synthesis (SHS). Within the VCS scheme, applications that are considered include Reactive Joining (RJ), Reactive Resistance Welding (RRW), and Spark Plasma Sintering (SPS). Under the SHS scheme, Combustion Foil Joining (CFJ) and Conventional SHS (CCJ) are discussed. Analysis of the relevant works show significant potential, particularly for the RJ, RRW, and CFJ approaches, in the joining of a variety of materials which are difficult, or impossible, to bond using conventional techniques. More specifically, it is shown that these methods can be successfully applied to the joining of: (i) dissimilar materials such as ceramics and metals and (ii) refractory materials, such as graphite, carbon-carbon composites, W, Ta, Nb, etc.      

Joining of zirconia ceramics in green state using a paste of zirconia slurry

A new technique for the green state joining of zirconia ceramics has been developed simply by using a paste of zirconia slurry. The interlayer of the joints has the same composition as the parent green bodies and, therefore, the mechanical properties of the joint are comparable to those of the bulk materials. Using this method, large and/or complex ceramic components could be produced cost effectively, because it minimizes the machining of the sintered body and eliminates the need for special equipment. This process can be applied to the joining of various other advanced ceramics.     

An analysis of deformation mechanism in the Si3N4–AgCuTi + SiCp–Si3N4 joints by digital image correlation

The composite filler shows more advantages than traditional brazing alloys, and has been widely introduced into joining ceramics or ceramics to metals. However, the underlying formation and strengthening mechanisms remained uncertain in the joint. In current research, SiCp (p = particle) was incorporated in Ag–Cu–Ti brazing alloy for joining Si₃N₄ ceramic. Nanoindentation method was introduced for probing the mechanical properties of reaction phases between the brazing alloy and SiCp. A novel formation mechanism model was thus proposed. In addition, optical microscope (OM) in conjunction with digital image correlation (DIC) techniques has been first applied to elucidate the deformation mechanism in the joint with and without SiC incorporation. The following reasons were believed to strengthen the brazed joint: load-transfer ability of SiCp, plastic relaxation in the brazing layer and CTE reduction of the composite filler.     

Facile joining of SiC ceramics with screen-printed polycarbosilane without pressure

Joining of SiC ceramics was successfully achieved at a relatively low temperature of 1500 °C without any pressure using pure polycarbosilane (PCS) as the joining material, which was distributed homogenously on the surface of SiC monolith through a screen printing method. The XRD pattern shows that the pyrolysis product of PCS is single-phase SiC. The interlayer thickness of the SiC joint is approximately 2 μm. This ultra-thin interlayer with lower possibility of the existence of defects contributes to the average shear strength of 105.8 ± 10.4 MPa, higher than that of other works using other preceramic polymers to the best of our knowledge. Due to the simplicity, low cost and high joining strength, the screen printing method using PCS as the joining material has good practicality in SiC ceramics joining.