共查询到19条相似文献,搜索用时 109 毫秒
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高分子材料具有易加工、韧性好、绝缘性能好等优点而被广泛应用,但热导率低又是绝大多数高分子材料的固有特性,也成为很多应用环境中的瓶颈问题。于是,研究人员尝试采用不同的基体、填料和工艺来制备绝缘导热的高分子复合材料,并取得了许多显著的研究成果。 相似文献
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导热高分子复合材料的研究进展 总被引:3,自引:0,他引:3
概述了国内外导热高分子复合材料的研制和应用情况,并从理论上介绍了导热高分子复合材料的结构特征、导热机理,以及导热理论模型。在此基础上探讨了优化导热高分子复合材料综合性能的方法。 相似文献
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真空条件下,以Al2O3和Al为原料,通过Al2O歧化法制备微细Al2O3/Al复合粉体.XRD和SEM分析表明:在反应温度为1200~1400℃时,随着温度的升高,粉体中氧化铝含量升高;冷凝温度约为550~750℃时,复合粉体中的氧化铝包括稳定晶型和不稳定晶型;冷凝温度约为1100~1300℃时,复合粉体中的氧化铝全部为稳定晶型;冷凝温度约为550~650℃时,复合粉体的平均粒径小于0.5μm;冷凝温度约为750℃时,铝熔化、微粒团聚;冷凝温度约为1100~1200℃时,铝形成铝珠,氧化铝为不规则状、平均粒径小于2μm;冷凝温度约为1300℃时,氧化铝为片状.因此,通过选取合适的反应温度、冷凝温度,可以控制Al2O3/Al复合粉体中氧化铝的含量、晶型和粒径. 相似文献
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以(3-氨丙基)三乙氧基硅烷(KH550)处理氮化硼/氧化铝(BN/Al2O3)导热粉体,在导热粉体表面引入氨基;通过熔融共混制备聚丙烯接枝马来酸酐(PP-g-MAH)增容的聚丙烯(PP)/BN/Al2O3导热绝缘复合材料。研究PP-g-MAH和导热填料的用量以及加工条件(转速、温度)对复合材料性能的影响。结果表明,在主机转速为300 r/min、PP-g-MAH为4g、导热填料的用量为50%时,复合材料的导热系数达到了0.7 W/(m·K),拉伸强度为17.65 MPa;添加相容剂后,复合材料和导热填料之间的相容性得到改善。 相似文献
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介绍了Al2O3-C-BN-AlON和Al2O3-C-BN-SiC系复合耐火材料的合成方法,比较和评价了这两种复合耐火材料的性能,指出了Al2O3-C-BN-SiC系复合耐火材料作为精炼和连铸用耐火材料,可望大幅度提高使用寿命。 相似文献
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Al2O3- SiC- C specimens were prepared using white fused corundum( 3- 1,≤1 and ≤0. 044 mm),Al2O3- SiC composite powders( d50≤5 μm),α-Al2O3micropowder( d50= 1. 2 μm),SiC powder( ≤0. 044mm),flake graphite( ≤0. 088 mm),Si powder( d50= 42. 8 μm) and B4C powder( d50≤10 μm) as main starting materials,and thermosetting phenolic resin as binder. 4%,8%,12% and 16%( in mass,the same hereinafter) of Al2O3- SiC composite powders substituted the same quantity of α-Al2O3micropowder + SiC powder.Effects of composite powder additions on apparent porosity,bulk density,cold modulus of rupture,cold crushing strength,hot modulus of rupture( 1 400 ℃),therma shock resistance( 1 100 ℃,water quenching) and oxidation resistance( 1 000 and 1 500 ℃) of Al2O3- SiC- C specimens after 180 ℃ curing,1 000 ℃ 3 h carbon-embedded firing and 1 500 ℃ 3 h carbon-embedded firing,respectively,were researched. The results indicate that:( 1) with the increase of Al2O3- SiC composite powder,cold strengths of the cured specimens decline,those of the specimens fired at 1 000 ℃ change a little,and those of the specimens fired at 1 500 ℃ change a little except for an obvious improvement of cold crushing strength;( 2) with the increase of Al2O3- SiC composite powder,hot modulus of rupture at 1 400 ℃ decreasesand thermal shock resistance enhances significantly;( 3) when Al2O3- SiC composite powder addition is4%,the oxidation resistance at 1 500 ℃ is the best,and the reason may be the composite powder is finer and more active,which is beneficial to form dense mullite protective layer to retard the O2diffusion into the specimens. 相似文献
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N. A. Dabizha V. S. Yakushkina A. A. Dabizha I. B. Smirnova O. L. Moiseeva 《Refractories and Industrial Ceramics》1990,31(1-2):25-27
Conclusions Following an investigation of the thermal aging at 800°C in air of ceramics based on Al2O3 TiO2 (Nos. 1–3) and Al2O3-TiO2-SiO2 (No. 4), it was established that the ceramics based on Al2O3-TiO2-SiO2 are the most heat-stable at 800°C over prolonged periods.Translated from Ogneupory, No. 1, pp. 21–23, January, 1990. 相似文献
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《Journal of the European Ceramic Society》2005,25(8):1285-1291
The mechanical properties and thermal stability of the Al2O3/Er3Al5O12 (EAG) eutectic ceramics have been investigated at very high temperature. The emissive properties of this eutectic ceramics have also been measured and its possibilities of application to an emitter have been discussed. The present eutectic ceramic has excellent high-temperature strength characteristics, showing that tensile yielding stress is approximately 300 MPa at 1650 °C and superior thermal stability at 1700 °C in an air atmosphere. The present material shows strong selective emission bands at wavelength 1.5 μm due to Er3+ ion. The emission bands of this material are nearly coincident with the sensitive region of GaSb PV cell, therefore, the Al2O3/EAG eutectic ceramic can be regarded as one of the promising emitter materials in TPV systems. 相似文献