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101.
利用往复压缩机的2根因裂纹报废的曲轴,截取其有用部分,用刚性联轴器成功对接成1根“新轴”,短时间内解决了压缩机无备轴影响生产的问题。 相似文献
102.
In times of increasing energy costs automotive light weight construction is gaining more importance. The production of hybrid compounds by forging is a promising method for manufacturing functional parts by applying resource‐saving process steps. The mechanical properties of these parts can be specifically adapted to the requirements. In compound forging of steel‐aluminum parts the two materials need to be heated to different forming temperatures. In this paper, the challenges and their methods for the development of a heating and forming strategy based on different material characteristics are presented. 相似文献
103.
《Journal of the European Ceramic Society》2014,34(12):2913-2924
SiC-fiber/SiCN ceramic matrix composites were manufactured by means of polymer infiltration and pyrolysis. The fiber preform was made by slurry infiltration and winding using a computer-controlled winding module. Multiple infiltration steps using a Si–C–N precursor were included to increase the density. The influence of the sintering conditions on the microstructure of the CMC was demonstrated.Pipe sections made of the CMC materials were joined using a laser-supported heating technology with an Y–Al–Si–O glass–ceramic filler. The thermal response of the CMC components was controlled by the anisotropic thermal conductivity. Fast heating by laser beam was achieved for elements rotating in the direction of the fiber winding. SEM micrographs of the joints showed the good wettability of the CMC by the glass–ceramic filler. Nearly defect-free joints were obtained using a nitrogen process atmosphere. The laser-supported technology was shown to be promising for the joining of CMC components. 相似文献
104.
Jing Zheng Scott P. Beckman Joe N. Gray Mufit Akinc 《Journal of the American Ceramic Society》2001,84(9):1961-1967
X-ray tomography has been used to investigate the density variations in SiC joints formed using polymer pastes. It has been demonstrated that X-ray tomography provides accurate bulk density measurements and volumetric density gradients. The results suggest that the magnitude of the applied pressure after green state joining and the amount of polymer (polycarbosilane, PCS) in the joining pastes influence the green density of the joints. All joints are prepared and applied in air atmosphere and at room temperature. The green densities of the joints increase from 54% to 66% of theoretical with the increase of the applied pressure from ambient to 138 MPa. Highest joint density without applied pressure is achieved using paste containing 50 vol% PCS. Furthermore, allylhydridopopolycarbosilane- (AHPCS-) containing pastes resulted in higher densities at the joint–matrix interface, indicating infiltration of polymer into the matrix. 相似文献
105.
Single-lap shear behaviour of carbon–epoxy composite bolted aircraft fuselage joints at quasi-static and dynamic (5 m/s and 10 m/s) loading speeds is studied experimentally. Single and multi-bolt joints with countersunk fasteners were tested. The initial joint failure mode was bearing, while final failure was either due to fastener pull-through or fastener fracture at a thread. Much less hole bearing damage, and hence energy absorption, occurred when the fastener(s) fractured at a thread, which occurred most frequently in thick joints and in quasi-static tests. Fastener failure thus requires special consideration in designing crashworthy fastened composite structures; if it can be delayed, energy absorption is greater. A correlation between energy absorption in multi-bolt and single-bolt joint tests indicates potential to downsize future test programmes. Tapering a thin fuselage panel layup to a thicker layup at the countersunk hole proved highly effective in achieving satisfactory joint strength and energy absorption. 相似文献
106.
指出钻孔咬合桩作为一种支护围挡结构,具有地质适应性强,工程造价低,施工速度快,对场地要求低等特点,特别是在抗渗漏水及对既有建筑稳定保护上具有优势,深入介绍了钻孔咬合桩作为深水基础围堰施工的方法及工艺,为类似工程施工提供了宝贵的经验。 相似文献
107.
Ph.V. Kiryukhantsev-Korneev A.N. Sheveyko N.V. Shvindina E.A. Levashov D.V. Shtansky 《Ceramics International》2018,44(7):7637-7646
Comparative study of Ti-C-Ni-Fe, Ti-C-Ni-Al, and Ti-C-Ni-Al/Ti-C-Ni-Fe coatings obtained by electro-spark deposition (ESD) using TiCNi electrode, magnetron sputtering (MS) of TiCNiAl target, and a combination of these methods (MS-ESD) was carried out. The coating microstructures and elemental compositions were studied by means of X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and glow discharge optical emission spectroscopy. The materials were tested in terms of their hardness, elastic modulus, elastic recovery, crack resistance, friction coefficient, and wear resistance under sliding, impact and abrasive conditions, as well as corrosion- and oxidation resistance. The work demonstrated that the utilization of a combined two-step MS-ESD technology permits to obtain bilayers made of Ti-C-Ni-Al/Ti-C-Ni-Fe coatings with improved crack-, wear- and oxidation resistance compared with their single-layered Ti-C-Ni-Al counterparts deposited by MS, and with reduced friction coefficient and enhanced corrosion resistance compared with ESD Ti-C-Ni-Fe coatings. 相似文献
108.
E. A. Levashov D. V. Larikhin D. V. Shtansky A. S. Rogachev H. E. Grigoryan J. J. Moore 《Journal of Materials Synthesis and Processing》2002,10(6):319-330
Two- and three-layer functionally graded PVD targets with a working layer (sputtering surface) based on TiN-TiB2 or TiN-Ti5Si3 formation via the technology of forced SHS compaction were considered. It was shown that rather wide (up to 1 mm) transition diffusional zones providing firm adhesion of the layers were formed between the working, intermediate, and third layers. The compositions TiN + TiB2 + 20%Cu and TiB2 + 50%Cu were found to be optimum for the intermediate (damping) and third layers of the three-layer PVD targets. The specific features of phase and structure formation of the two- and three-layer products with the working layer based on TiN-TiB2 and TiN-Ti5Si3 were elucidated. Variation of the chemical oven mass exerted a noticeable effect of reduction of the residual porosity and enlarging of the grains of the product phases owing to prolongation of the time for secondary structure formation. The relationship of the hardness of the layers in the functionally graded target on the chemical oven mass allow prediction of the properties of the resultant graded material systems. 相似文献
109.
三元层状陶瓷Ti3SiC2的高温氧化行为 总被引:6,自引:0,他引:6
研究了以自蔓延准热等静压和热处理工艺制备出的高纯、致密的Ti3SiC2块体材料的高温氧化性能.采用XRD,SEM和EMPA分析了氧化膜表面形貌、组织结构和成分.研究结果表明,在1000℃的空气中,Ti3SiC2陶瓷材料具有优异的抗氧化性能,且恒温氧化行为与循环氧化行为相似.其在120h内的氧化动力学曲线趋近于直线-抛物线规律.随着氧化时间的延长,氧化膜由TiO2和SiO2混合物组成的单层结构逐渐过渡到双层结构.双层结构的内层为固溶了SiO2的TiO2层,而外层为纯金红石相. 相似文献
110.