共查询到19条相似文献,搜索用时 140 毫秒
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采用SHS/PHIP工艺制备了致密的TiC-Al2O3-Fe系金属陶瓷,研究了延迟时间,高压特续时间,压力及Fe含量对合成TiC-Al2O3-Fe金属陶瓷实度的影响,结果表明,采用SHS/PHIP技术制备了TiC-Al2O3-Fe系金属陶瓷时,合成产物中气体的排放,液相的存在及组成相之间的润湿性是制备密实材料的关键。 相似文献
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通过自蔓延高温合成结合准热等静压法(SHS/PHIP)制备出了致密度为97.7%的TiC-Al2O3-20Fe3合金陶瓷(TAF20),分析了金属陶瓷的相组成、微观组织及性能。结果表明:金属陶瓷由TiC,Al2O3陶瓷颗粒和Fe粘结相组成;粘结相中Fe与Al2O3之间的界面光滑,与TiC之间有一薄的扩散层;TAF20金属陶瓷的抗强度和抗压强度分别为890MPa和18.4GPa。 相似文献
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掺杂聚苯胺磁化率的研究 总被引:6,自引:0,他引:6
分别研究了浓H2SO4掺杂本征态聚苯胺(PAn)、HCl掺杂PAn以及FeCl3掺杂这两种聚安在地的磁化率。通过研究磁化率的变化曲线,我们得到了一些有意义的结果:浓H2SO4掺杂PAa和HCl掺杂PAn的磁化率变化规律不同;FeCl3掺杂浓H2SO4-PAn材料可以获得比FeCl3掺杂HCl-PAn材料更高的磁化率;FeCl3在掺杂HCl-PAn材料和浓H2SO4-PAn材料时,FeCl3在这两种 相似文献
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SHS/PHIP技术制备TiC—30Fe金属陶瓷的显微组织及形成过程研究 总被引:5,自引:1,他引:4
通过自蔓延高温合成结合准热等静压法制备出了致密度为96.3%的TiC-30wt%Fe金属陶瓷。分析了金属陶瓷的结构和组织,讨论了SHS/PHIP制备金属陶瓷的材料结构形成过程。结果表明,金属陶瓷由近乎球形TiC颗粒和Fe粘结相组成。粘结相Fe与TiC之间有一较薄扩散层。 相似文献
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Al-TiO2-C-Ti-Fe体系反应过程研究 总被引:4,自引:0,他引:4
采用DSC和XRD对不同Fe含量Al-TiO2-C-Ti-Fe体系的燃烧反应过程进行了研究。结果表明,Al-TiO2-C-Ti-Fe体系的反应是分步进行的。在高温区以金属间化合物的分解及Ti、C反应为主;在低温区则随着Fe含量的不同存在不同的反应:Al-TiO2-C-Ti以Al、Ti的反应为主,Al-TiO2-C-Ti-20wt%Fe以Al、Ti及Al、Fe反应为主,同时还存在Al、TiO2及Fe、Ti反应,而Al-TiO2-C-Ti-50wt%Fe则以Fe、Al和Fe、Ti反应为主。 相似文献
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研究了由多种Lewis酸(FeCl3、AlCl3、TiCl4、BF3·OEt2等)与SOCl2配制成的一类新型聚合引发剂,比较了它们对α-蒎烯的引发复合性能。结果表明复合引发体系的活性比之单独的Lewis酸均大幅度提高,活性大小顺序为:BF3·OEt2/SOCl2>TiCl4/SOCl2≈AlCl3/SOCl2>FeCl3/SOCl2,与它们的配位能力大小顺序一致。系统考察了TiCl4/SOCl2体系的聚合性能,研究了复合引发剂组分比、溶剂、活泼单体苯乙烯、外加Lewis碱以及聚合条件等对α-蒎烯聚合动力学、产物分子量及其分子结构的影响,据之讨论了该复合引发剂的作用机制,提出了活性种本质的看法。 相似文献
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The microstructure and composition of TiC-A12O3/Fe functionally graded materials (FGM) prepared by self-propagating high temperature synthesis and pseudo-hot isostatic pressing (SHS/ PHIP) were studied, and the resisting thermal shock behaviors were analyzed. The results show that TiC-A12O3/Fe FGM has graded composition distribution. No cross-section crack through the layers was found in the tests of thermal shock and fatigue. 相似文献
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《Materials Chemistry and Physics》2005,89(2-3):238-243
Mullite/Mo functionally graded material (FGM) was developed with a powder metallurgy process. Microscopic observations revealed that the microstructure of the mullite/Mo FGM had a gradual stepwise variation. The thermomechanical properties of the mullite/Mo system had graded distributions that depend on the composition variation across the thickness. Thermal shock tests were done on the FGMs and on monolithic mullite. The FGM specimens had better thermal shock resistance than did monolithic mullite. The thermal shock resistance of FGMs was influenced by the sintering-induced residual thermal stress. Cracks caused by thermal shock were observed, and the mechanism of crack formation was discussed. 相似文献
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H. Hamatani N. Shimoda S. Kitaguchi 《Science and Technology of Advanced Materials》2013,14(2):197-203
Low Pressure Plasma Spraying (LPPS) is a promising coating method for Functionally Graded Material (FGM) expected to beable to reduce the thermal stress in high temperature environments such as a gas turbine. In this paper, we report the effect of the composition profile and coating density of LPPS sprayed FGM, consisting of ZrO2–8 wt%Y2O3 (YSZ) top coating, YSZ–Ni–20 wt%Cr (NiCr) FGM coating, NiCr under coating and copper substrate, on the thermal shock resistance evaluated by a modified temperature difference test. The density of YSZ and NiCr coating was successfully controlled by the chamber pressure and initial particle size in the range from 5.43 to 5.79 g/cm3 and from 7.89 to 8.09 g/cm3, respectively. For an YSZ composition profile from NiCr under coating to YSZ top coating (in FGM), the highest thermal shock resistance was obtained when the fraction of YSZ increased with gentleslope just over NiCr coating and acute slope just under YSZ coating. Also, the higher density coatings tended to perform the higher thermal shock resistance. Initial cracks formed in the YSZ top coating propagated into YSZ parts in FGM coating through the grain boundary of YSZ and/or the interface between flattened NiCr and YSZ particles. After the cracks connected, the coupled cracks caused the coating spallation.©2003 Elsevier Science Ltd. All rights reserved. 相似文献