Effect of coating on the microstructure and thermal conductivities of diamond-Cu composites prepared by powder metallurgy
Effect of coating on the microstructure and thermal conductivities of diamond-Cu composites prepared by powder metallurgy
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涂层对粉末冶金金刚石-Cu复合材料微观结构和导热性能的影响
DOI：
10.1016/j.compscitech.2011.06.012
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发表时间：
2011-09-09
影响因子：
9.1
通讯作者：
Qu, Xuanhui
中科院分区：
文献类型：
--
作者：
Ren, Shubin;Shen, Xiaoyu;Qu, Xuanhui
金刚石与铜直接复合而成的金刚石-铜复合材料，由于界面较弱，热导率较低，但由于化学不相容性，其热阻较高。本文提出了一种通过在金刚石表面涂覆强碳化物形成元素来增强金刚石与铜界面结合的新方法。通过真空微沉积法在金刚石表面沉积Ti或Cr。在金刚石颗粒与铜结合前，先在金刚石颗粒表面包覆一定厚度的Cr或Ti层，可大大降低金刚石-铜复合材料的界面热阻。导热系数也增加了几倍。Cr涂层比Ti涂层能更有效地降低金刚石与Cu之间的界面热阻。此外，Cr对Cu基体的导热系数影响较小，从而使Cr涂层金刚石-Cu复合材料具有更高的导热系数。通过真空微沉积技术。金刚石颗粒表面上的Cr以接近金刚石的Cr 7 C3和2：1的纯Cr外层的形式存在。最佳厚度为0.6-0.9 μ m，在此厚度下，70vol%金刚石-铜复合材料的热导率可提高4倍，最高可达657 W/mK。在这项工作中，提出了一个原始的理论模型来估计具有一定厚度的夹层的复合材料的热导率。该模型的预测值与实验值吻合较好。(C)2011爱思唯尔有限公司保留所有权利。
Diamond-Cu composites from the direct combination of diamond and Cu show low thermal conductivities due to weak interface and high thermal resistance as a result of chemical incompatibility. In this paper, a new method is proposed to strengthen interfacial binding between diamond and Cu by coating strong carbide-forming elements, e.g.. Ti or Cr on the surface of the diamond through vacuum micro-deposition. Interfacial thermal resistance of diamond-Cu composites is greatly decreased when diamond particles are coated by a Cr or Ti layer of a certain thickness before combining with Cu. Thermal conductivity is also increased several times. Cr coating can reduce more effectively interface thermal resistance between diamond and Cu than Ti coating. Moreover, it has a smaller negative impact on the thermal conductivity of the Cu matrix, resulting in higher thermal conductivity of Cr-coated diamond-Cu composites. Through the vacuum micro-deposition technology. Cr on the diamond particle surface is present in the form Cr7C3 near diamond and a pure Cr outer layer at 2:1. The optimum thickness is within 0.6-0.9 mu m; at this depth, the thermal conductivities of 70 vol% diamond-Cu composites can be increased four times and reach as high as 657 W/m K. In this work, an original theoretical model is proposed to estimate the thermal conductivities of composite materials with an interlayer of a certain thickness. The predicted values from this model are in good agreement with the experimental values. (C) 2011 Elsevier Ltd. All rights reserved.