• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>2014 Joint IEEE International Symposium on the Applications of Ferroelectrics, International Workshop on Acoustic Transduction Materials and Devices amp; Workshop on Piezoresponse Force Microscopy >Fabrication and thermophysical properties of short graphite fiber/Cu composites with Mo2C coating by vacuum pressure infiltration
【24h】

Fabrication and thermophysical properties of short graphite fiber/Cu composites with Mo2C coating by vacuum pressure infiltration

机译：Mo 2 C涂层的短压石墨纤维/ Cu复合材料的真空压力浸渗法制备及其热物理性质

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

High-performance mesophase pitch-based graphite fiber reinforced metal matrix composites offer a good thermal conductivity and tailorable coefficient of thermal expansion. These composites are regarded as a promising heat dissipation materials for electronic packaging application. It is reported that short graphite fiber/Al composites were fabricated by vacuum pressure infiltration, which is a suitable procedure for the fabrication of complex shaped components at high production rates and low cost. The thermal conductivity of short fiber/Al composites is lower than 230 W m−1 K−1. It is expected that the composites using copper as the matrix, which has a higher thermal conductivity and lower coefficient of thermal expansion than aluminum, may have a better thermal properties. However, there is few investigation on fabrication of graphite fiber/Cu composites since copper does not wet graphite. This work focuses on the fabrication of short graphite fiber/Cu composites for thermal management application by vacuum pressure infiltration technique. A Mo2C coating was synthesized on the surface of graphite fiber through molten salts method for improving the wetting between graphite fibers and copper. Certain Grfs reacted with molybdenum oxides powders in a molten salts mixture composed of NaCl-KCl at 1000 °C for 30 min under a flowing argon atmosphere. The obtained coating is compact and homogenous with the thickness of 0.3 μm. Copper was infiltrated into Mo2C-coated graphite preform at 1150 °C with low pressure and Cu matrix composites with 20 vol%–40 vol% fibers were fabricated. Due to the unidirectional compression in the perform and infiltration process, the fibers were uniform distribution in the plane perpendicular to the press direction (X-Y plane) and showed a two dimensional orientation. The interface of composites was examined by EDS line-scan. Results show that there was - opper infiltrated into the Mo2C interlayer. A good adhesion was observed in composites in which the Mo2C interlayer tightly adhered to both fiber and Cu matrix. The obtained composites present high relative density above 99.5%. With increasing volume fraction of fiber from 20% to 40%, the thermal conductivity of composites in X-Y plane slightly decreased from 356 W m−1 K−1 to 311 W m−1 K−1. The coefficient of thermal expansion in X-Y plane decreased from 14× 10−6 to 7 × 10−6 K−1. The experimental values of thermal conductivities of composites were compared with the theoretical calculation. With the introduction of Mo2C interlayer, the interface thermal conductance of graphite fiber/Mo2C interlayer/copper matrix had to be taken into consideration. So the effective thermal conductivity of coated fiber was firstly calculated by using the acoustic mismatch model (AMM). Then, a model of Maxwell-Garnett effective medium approach on the anisotropic short fiber reinforcement was used to estimate the thermal conductivity of composites. The result showed that the theoretical predictions are in good agreement with the experimental values. The thermal conductivity of composites could be further improved if perform with single axile orientation fiber was infiltrated.
机译：高性能中间相沥青基石墨纤维增强金属基复合材料具有良好的导热性和可定制的热膨胀系数。这些复合材料被认为是电子包装应用中有希望的散热材料。据报道，通过真空压力渗透法制备了短的石墨纤维/铝复合材料，这是用于以高生产率和低成本制备复杂形状的部件的合适方法。短纤维/ Al复合材料的导热系数低于230 W m-1 K-1。可以预期，与铝相比，以铜为基质的复合材料具有更高的热导率和更低的热膨胀系数，可以具有更好的热性能。然而，由于铜不会润湿石墨，因此很少有研究制造石墨纤维/铜复合材料。这项工作的重点是通过真空压力渗透技术制造用于热管理应用的短石墨纤维/铜复合材料。通过熔融盐法在石墨纤维表面合成了Mo2C涂层，以改善石墨纤维与铜之间的润湿性。在流动的氩气气氛下，某些Grfs在由NaCl-KCl组成的熔融盐混合物中与氧化钼粉末反应30分钟。所获得的涂层致密且均匀，厚度为0.3μm。在低压下，将铜在1150°C下渗入涂有Mo2C的石墨预成型坯中，并制成纤维含量为20％至40％的铜基复合材料。由于表演和渗透过程中的单向压缩，纤维在垂直于压榨方向的平面（X-Y平面）中呈均匀分布，并呈现二维取向。通过EDS线扫描检查复合材料的界面。结果表明，有-opper渗入Mo2C中间层。在Mo2C中间层牢固地粘附在纤维和Cu基体上的复合材料中，观察到了良好的粘附性。所获得的复合材料具有高于99.5％的高相对密度。随着纤维体积分数从20％增加到40％，X-Y平面中复合材料的热导率从356 W m-1 K-1略微降低到311 W m-1 K-1。 X-Y平面中的热膨胀系数从14×10-6降低到7×10-6 K-1。将复合材料的热导率实验值与理论计算值进行了比较。随着Mo2C夹层的引入，必须考虑石墨纤维/ Mo2C夹层/铜基体的界面热导。因此，首先使用声学失配模型（AMM）来计算涂层纤维的有效导热系数。然后，采用各向异性短纤维增强的Maxwell-Garnett有效介质方法模型来估计复合材料的导热系数。结果表明，理论预测值与实验值吻合良好。如果渗入单轴取向纤维，则可以进一步提高复合材料的导热性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号