共查询到13条相似文献,搜索用时 62 毫秒
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采用水淬法对以Na2O-B2O3-SiO2体系玻璃焊料连接的常压烧结碳化硅试条的抗热震性能进行了研究. 对不同温度下淬火后接口以及断面处微观结构进行了比较与分析, 并对比了不同淬火温度以及固定淬火温度为150℃时多次热循环后连接试条的残余弯曲强度. 结果表明, 对于单次淬火, 当淬火温度为150℃时, 由于热应力引起中间层内部微裂纹扩展, 导致残余弯曲强度迅速降低到(152±28) MPa. 淬火温度在150℃~320℃时, 中间层内部裂纹保持在亚临界状态, 相应弯曲强度基本保持在140 MPa. 继续升高淬火温度至420℃时, 裂纹进一步扩展, 试条残余弯曲强度迅速降低至(32±8) MPa. 对于多次热循环, 当淬火温度固定在150℃时, 经多次热循环, 残余弯曲强度与热循环次数变化不明显, 基本保持在120 MPa左右, 这说明在150℃以下淬火, 连接试条具有较好的抗热循环冲击性能. 相似文献
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碳化硅陶瓷和金属铌及不锈钢的扩散接合 总被引:8,自引:0,他引:8
研究了碳化硅陶瓷和金属Nb的相反应,显微组织结构和Nb2C、Nb5Si3Cx,NbC和NbSi2的形成过程,分析了反应相对霎头强度的影响。 相似文献
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T. Yamada H. Sekiguchi H. Okamoto S. Azuma A. Kitamura K. Fukaya 《Materials at High Temperatures》2013,30(4):193-200
A method of diffusion bonding SiC or Si3N4 to Nimonic 80A was developed to establish the fundamental technology for the application of ceramics to machinery components used at elevated temperature. An analysis of the thermal stress that occurs in ceramic/Nimonic 80A bonded composites was done using the finite element method, and a bonding experiment based on the analytical results was conducted. The composites were produced by the insert metal bonding method, using varying thickness of Ni, W, Kovar, Cu and so on. It was found that the residual thermal stress in the ceramic part of the composite was extremely low and that the composite had a tensile strength of more than 98 MPa at room temprature. Furthermore, the paper describes the feasibility of the application ofthis bonding method to components for marine diesel engines. 相似文献
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Greta Merkininkaite Darius Gailevicius Laurynas Staisiunas Egle Ezerskyte Rokas Vargalis Mangirdas Malinauskas Simas Sakirzanovas 《Advanced Engineering Materials》2023,25(17):2300639
Herein, the fabrication of hard ceramic SiOC 3D microstructures by precursor synthesis, laser lithography, and pyrolysis combination is proposed. Precursors are hybrid organosilicon materials prepared via sol–gel method using trimethoxymethylsilane and 3-(trimethoxysilyl)propyl methacrylate, which has an acrylate functional group enabling laser photopolymerization process. Hard 3D ceramic structures (hardness up to ≈15 GPa, reduced elastic modulus ≈105 GPa) from soft organometallic derivatives are obtained after high-temperature pyrolysis under nitrogen atmosphere. The advantage of the proposed method is the absence of shrinkage defects leading to a uniform repetitive decrease in the volume of printed microstructures. In contrast to slurry-based printing technology, the proposed method is focused on homogeneous monolithic molecular resins resulting in visual smooth surfaces of prepared microstructures. Moreover, the printing resolution of the proposed method is substantially improved through the absence of predispersed ceramic microparticles in mixtures, which is a necessary element in a slurry-based technology. 相似文献
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对采用SY-14胶粘剂生产胶部件的随炉件剥离强度进行了试验研究。结果表明,胶膜厚度,固化胶层度,尺寸和结构形式等对剥离强度都有影响,剥离强度指标应从结构设计用缺陷要求和胶粘剂性能统计处理的综合考查而确定。 相似文献
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Phase Reactions and Diffusion Path of the SiC/Cr System 总被引:1,自引:0,他引:1
Solid-state bonding at pressureless-sintered SiC has been carried out using 25-m Cr foil at temperatures from 1373 to 1773 K for 1.8 ks in vacuum. The formation of reaction phases and microstructures at the interface between SiC and Cr was investigated by X-ray diffraction and microprobe analysis. At the bonding temperature of 1373 K the cubic Cr23C6phase formed next to Cr, and the hexagonal Cr7C3 phase formed next to SiC. At 1473 K the cubic phase Cr3SiCx appeared additionally on the SiC side. At 1573 K the complete diffusion path was established. Upon increasing the joining temperature beyond 1573 K all the chromium was consumed, and Cr23C6 and Cr3SiC
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dissolved. A layered structure consisting of SiC/Cr5Si3
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/Cr7C3/Cr5Si3
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/SiC occurred. 相似文献
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综述了SiC/Si3 N4 复合粉体的力学性能和制备方法 ,提出了一种制备纳米级SiC/Si3 N4 复合粉体的新方法 ,并通过热力学分析提出了合成条件 相似文献
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Si_3N_4陶瓷与Si_3N_4陶瓷及金属连接的研究进展 总被引:3,自引:0,他引:3
对Si3N4陶瓷与Si3N4陶瓷、Si3N4陶瓷与金属的连接工艺进展进行了系统的介绍 ,重点评述了Si3N4直接钎焊法、Si3N4间接钎焊法、Si3N4陶瓷玻璃焊法的研究进展 ,并提出了今后研究的重点 相似文献
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酚醛树脂基胶粘剂的高温粘接性能 总被引:2,自引:0,他引:2
以酚醛树脂为基体,以碳化硼(B4C)粉末为改性填料制备高温胶粘剂,并对碳材料进行粘接.粘接样品在200℃固化后,随即在马弗炉中进行1200℃的高温处理.在1000,1400,1800℃测试粘接样品的高温粘接性能.结果表明,改性酚醛树脂具有较好的高温粘接性能,且随着测试温度的提高,粘接样品的粘接强度随之提高.高温下改性组分结构、形态的变化对酚醛树脂的高温粘接性能有着重要的影响.适量B2O3的形成有利于在粘接界面处形成化学键合力,从而提高界面粘接能力;但B2O3在高温下熔融并呈现为玻璃相,致使破坏应力迅速扩展延伸,从而引起高温环境下粘接强度的迅速降低.随着温度的升高,B2O3玻璃相在粘接胶层中的含量逐渐减少,对高温粘接性能的影响降低,粘接制品的高温粘接性能随之提高,1800℃测试温度下的粘接强度达到5.22MPa. 相似文献