共查询到19条相似文献,搜索用时 117 毫秒
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莫来石晶须制备新工艺与生长机理 总被引:8,自引:0,他引:8
本文首次提出了用Al2O3-SiO2玻璃粉高温热处理制取莫来石晶须的新工艺.采用XRD、SEM和TEM等手段研究了热处理温度制度及气氛对莫来石晶须生长的影响,确定了制备莫来石晶须的最佳工艺参数,所得莫来石晶须的直径为0.4~1.2Pm、长径比为10~40,其生长方向为c轴方向,生成物中莫来石晶须的含量接近98vol%.探讨了用Al2O3-SiO2玻璃粉制取莫来石晶须的生长机理. 相似文献
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研究了Al2O3、Al2o3/TiB2和Al2O3/TiB2/SiCW三处陶瓷材料在不同条件下的擦靡损特性。结果表明:三种陶瓷材料与硬质合金摩擦副的摩擦系数随温度温度的增加有不同的变化规律,摩擦表面的X射线衍射分析表明,摩擦系数的变化与陶瓷物膜的和结构有关,在高温下Al2O3/TiB2陶瓷材料摩擦表面形成了具有优良的高温润性的TiO2氧化膜,因而TiB2的加入明显改善了Al2O3陶瓷材料 摩擦磨损 相似文献
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晶须增韧补强陶瓷基复合材料的若干关键技术研究(Ⅰ):晶界和界面的调控 总被引:1,自引:1,他引:0
根据各种助烧剂在相应的氧氨玻璃中的作用,通过晶界相预合成和改变Al2O3和MgO的添加量,研究了不同La/Y比及Al2O3和MgO含量对SiC(w)/Si3N4复合材料力学性能的影响,从而实现了对晶界和界面的调控,优化了助烧剂体系和制备工艺,达到了最佳的晶须增韧强效果。 相似文献
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H3PO4—H2SO4体系铝型材化学抛光研究 总被引:4,自引:1,他引:3
用反射光法和重量法研究了铝合金的抛光液中各组分和操作条件对抛光效果的影响,讨论了抛光机理,并得出了最佳溶液组成及操作条件。生产应用表明,该工艺具有光亮度高、反应温度低、无黄烟等优点,完全可以替代H3PO4-H2SO4-HNO3体系铝合金的化学抛光。 相似文献
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液相外延生长磁性石榴石薄膜中铋的分凝系数与生长率的关系 总被引:2,自引:0,他引:2
在Bi2O3-PbO-B2O3复合助熔剂中,采用等温浸渍液相外延技术在GGG基片的(111)面上生长了(Bi,Al):YIG薄膜。通过调整过冷度和基片转速来改变薄膜的生长速率。测量了外延膜中铋的含量。给出了铋的分凝系数的表达式,并计算了铋的分凝系 。 相似文献
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反应烧结Si_3N_4陶瓷及零件的研制EI 总被引:1,自引:0,他引:1
本文研究了成分配比对反应烧结氮化硅的烧结密度及相组成的影响,发现采用Y_2O_3和La_2O_3为烧结助剂时,在不加入其它催化剂的条件下,配合料中硅粉的最佳添加量为12~30wt%。采用热压铸成型与反应烧结相结合的工艺,可用Si_3N_4陶瓷制造出陶瓷发动机叶片等零件。 相似文献
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A alumina borate whisker with Bi(OH)3 coating was prepared by a chemical method. The coated whiskers were sintered at various temperatures. The coated whisker-reinforced pure aluminum matrix composite was fabricated by squeeze casting method. The microstructures of the coated whiskers and coated composites with the different sintering temperature of whisker preform were studied, and the tensile properties of the coated composites at room temperature were also investigated. It can be found that the microstructures of coatings on the whisker surfaces and at the interface in the coated composites are strongly dependent on the sintering temperature of whisker preform. The ultimate tensile strength and elongation to fracture of the coated composites increased with the increasing of sintering temperature of the whisker preform. 相似文献
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In this paper, the aluminum borate whisker (ABOw) and BaPbO3 particles (BPOp)/Al hybrid composite with radiation protection function was fabricated by squeeze casting technique. The microstructure and properties of the hybrid composite were investigated. The test results show that BPOp and aluminum matrix have a reaction, and this reaction forms a coating on the surface of ABOw. The introduction of BPOp increases radiation protection function of the matrix evidently, at the same time, the hybrid composite has better mechanical properties compared with the aluminum matrix and ABOw/Al composite. 相似文献
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概述了钛酸钾、氧化锌、硼酸铝等陶瓷晶须增强聚合物基复合材料的研究进展,探讨了晶须含量、晶须表面处理、材料前处理方法等对提高复合材料力学性能及摩擦学性能的影响,明确了适当的表面改性方法可以使晶须的增强效果更为明显,指出了在晶须/聚合物结合面微观形态观察和分析方面的不足,提出了构建晶须/聚合物复合材料的理论模型、预测复合材料性能的研究方向. 相似文献
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Using a space-dependent rate-equation model and considering the effect of pump beam quality, the optimum pump condition for a fiber-coupled diode end-pumped neodymium yttrium aluminum borate laser has been determined. Under optimum pump conditions, greater than 10% optical-to-optical conversion efficiency was obtained when the laser was pumped by a fiber-coupled laser diode with good beam quality. The influence of pump beam quality on the conversion efficiency is also discussed. 相似文献
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《Materials Chemistry and Physics》2007,101(2-3):499-504
Nanowires made of aluminum borate formed of Al18B4O33 have been synthesized in high yield by improving the traditional chemical flux method for the growth of aluminum borate with the fibrous structure. In this study, aluminum powder was added into the aluminum oxide and boron oxide reactants as an additive in order to control the morphology of the final products. The chemical method reported here is utilized to decrease the diameters of traditional aluminum borate fiber into nanoscale and to increase their lengths. The optimum experimental parameters and possible growth mechanism for the compound nanowires have been presented. 相似文献