共查询到10条相似文献,搜索用时 109 毫秒
1.
A vacuum centrifugal-thermite process was used to prepare ceramic-lined pipes rapidly. The ceramic layer was dense, and the grain size was smaller than that produced under atmospheric pressure, resulting in improved mechanical properties. 相似文献
2.
Shuang-Xi Wang Kai-Ming Liang Shou-Ren Gu Xian-Hui Zhang 《Journal of the American Ceramic Society》2001,84(12):3043-3044
A ceramic-lined steel pipe was fabricated using a self-propagating high-temperature synthesis gravitational-thermite process. Some rare-earth oxides and glass powders were added to the aluminothermite. The experimental results showed that the ceramic liner consisted of three phases: corundum (Al2 O3 ), glass, and iron particles. Neither hercynite (FeO·Al2 O3 ) nor iron ions existed in the liner of the composite pipe. 相似文献
3.
4.
O. Odawara T. Fujita A. V. Gubarevich H. Wada 《International Journal of Self-Propagating High-Temperature Synthesis》2018,27(4):228-235
Thermite and related processes have attracted considerable attentions as highly useful technologies for material and energy supplies in extreme environments such as geothermal and disaster-stricken areas as well as in space exploration. As part of the development of casing pipes used in geothermal power plants started from the 1970s, long ceramic-lined pipes have been obtained via thermite reaction under effective centrifugal force without any additional heat treatment [Centrifugal-Thermite (C-T) process]. The potentials of the ceramic-lined pipes in deeper geothermal utilizations are revalidated in details by reviewing the results obtained through the erosion-corrosion tests carried out under the conditions of high velocities (up to 100 m/s) and various acidities (from pH 2.0 to pH 4.0) of two-phase flows provided by the geothermal field test apparatus at the Onikobe geothermal power plant in Japan. By reducing the FeO content of the ceramic layer processed under proper additives and reactant amounts, the tested ceramic-lined pipes were significantly improved compared to highly corrosion-resistant stainless steels. The technological advantages obtained through the development of the C-T process can show a useful model to promote thermite-related technologies onward. 相似文献
5.
6.
交变磁场对重力SHS制备复合管微观结构和机械性能的影响(英文) 总被引:1,自引:0,他引:1
将交变磁场引入自蔓延高温合成反应,研究其对Al2O3复合管陶瓷层结构和力学性能的影响.结果表明:交变磁场可以促进燃烧反应的进行,随着磁感应强度的增加,α-Al2O3的枝晶尺寸减小,形态逐渐向细小的等轴晶形态过渡.复合管的抗压强度和抗剪强度随着磁感应强度的增加而增加.其中当磁感应强度为0.20T时,抗压强度和抗剪强度分别达418MPa和19.5MPa,比未引入交变磁场前分别提高了19.1%和21.9%. 相似文献
7.
Zhen-Yan Deng Guo-Jun Zhang Motohide Ando Tatsuki Ohji 《Journal of the American Ceramic Society》2002,85(7):1793-1803
Previous experimental results showed that a ceramic/superplastic laminate exhibited multiple cracking in ceramic layers during a three-point bending test. In this work, a model analysis has been developed based on bending theory. It reveals that there are two basic processes that occur after a ceramic layer fractures: one is a relaxation process of the residual stress in the ceramic layer, due to the confinement by the superplastic layers; the other is a shear process of superplastic flow, which originates from the difference in strain rate between the fractured and unbroken ceramic layers. The total stress in an as-fractured ceramic layer is the sum of the residual stress and a shear-accumulated stress, depending on time. When the total stress at a critical distance from the fractured surface exceeds the fracture strength of a ceramic layer, new cracking occurs. There is a critical roller speed below which no multiple cracking occurs, depending on specimen dimensions and material properties. The number of multicracks in one ceramic layer decreases with the progress of the fracture in the laminate, due to the decrease in shear-accumulated stress. The theoretical predications are in good agreement with the experimental results. Moreover, the variations in fracture energy of the laminate due to the multiple cracking are discussed in detail. 相似文献
8.
《Ceramics International》2019,45(12):14669-14674
Active-metal-brazing aluminium nitride (AMB-AlN) ceramic substrate with high thermal conductivity can provide a good alternative to conventional substrates in the high-temperature applications. However, the reliability of ceramic substrate when exposed to thermal cycling is still an issue. The aim of this study is to address the cyclic growth of warpage and stress of AMB-AlN ceramic substrate subjected to cyclic thermal loading (20-200-20 °C), which is of great significance for exploring the failure mechanism of ceramic substrate. The experimental results show that there is a hysteresis between the curves of bending height in the heating and cooling process, which can be explained by the Bauschinger effect. In addition, after five thermal cycles, the bending height of the ceramic substrate accumulates, showing a thermal ratcheting effect. By performing finite element analysis, it is also demonstrated that the warpage and stress of the ceramic substrate accumulates during the cyclic process. Furthermore, the stress on the ceramic layer is caused by the sum of the equivalent plastic strain of the copper layer and the filler metal, which is related to the thickness of the copper layer and the filler metal. 相似文献
9.
10.
MnO2对自蔓延高温合成陶瓷复合钢管陶瓷层结构和性能的影响 总被引:3,自引:0,他引:3
采用MnO2作为添加剂自蔓延高温合成法制备了具有Al2O3和FeAl2O4陶瓷层的复合钢管,研究其对陶瓷层和过渡层的结构和性能的影响.结果表明:添加了MnO2后,陶瓷层表面晶粒排布更加致密,陶瓷层的内表面为层叠状的Al2O3细晶和少量的FeAl2O4;过渡层为Al2O3和混入的FeAl2O4外,还含有SiO2和MnO2,过渡层出现了向钢基体中渗透的网状结构.MnO2的加入并未改变复合钢管Al2O3和FeAl2O4陶瓷层的物相.加入4%(质量分数)MnO2的复合管的抗压度强度和陶瓷层的抗剪强度分别达到416 MPa和19.2 MPa,比未添加MnO2的样品分别提高了18.2%和12.3% 相似文献