Interface reactions between silicon carbide and interlayers in silicon carbide-copper metal-matrix composites
Interface reactions between silicon carbide and interlayers in silicon carbide-copper metal-matrix composites
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DOI：
10.1016/j.jnucmat.2007.01.022
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发表时间：
2007-05-31
影响因子：
3.1
通讯作者：
Bolt, H.
中科院分区：
文献类型：
--
作者：
Koeck, T.;Brendel, A.;Bolt, H.
碳化硅纤维增强铜基复合材料被认为是未来聚变堆偏滤器的新一代散热材料。偏滤器暴露在强烈的粒子轰击和高达15兆瓦m(-2)的热负荷下。该组件由面向等离子体的材料组成，该材料结合到主动冷却的散热器上。K-1铜具有约400Wm(-1)的高导热系数，是一种很有前途的散热器材料。为了提高铜在工作温度(823K)下的力学性能，采用直径为140微米的碳化硅纤维来增强面向等离子体的材料与散热片之间的界面区域。推出试验表明，在无中间层的情况下，碳化硅纤维与铜基的结合力很低。为了提高纤维与基体的结合力，在用磁控溅射法沉积铜之前，在纤维表面涂覆一层厚度为300~400 nm的铬和钨。对这些改性纤维的推出测试表明，与没有夹层的纤维相比，粘附性显著提高。923K热处理后的X射线衍射谱表明，样品中有碳化铬(Cr23C6，Cr3C2)的形成，没有硅化铬的存在。在W中间层的情况下，检测到W2C形成，也没有钨硅化物。通过单纤维拉伸试验，研究了反应区对纤维极限拉伸强度的影响。没有夹层的纤维在923K热处理后的极限拉伸强度保持在约2200兆帕。分别含有铬和钨夹层的纤维在923K热处理后显示出大约30%的极限拉伸强度下降。(C)2007 Elsevier B.V.
Novel copper matrix composites reinforced with silicon carbide fibres are considered as a new generation of heat sink materials for the divertor of future fusion reactors. The divertor is exposed to intense particle bombardment and heat loads of up to 15 MW m(-2). This component consists of the plasma-facing material which is bonded to the actively cooled heat sink. Due to its high thermal conductivity of about 400 W m(-1) K-1 copper is a promising material for the heat sink. To increase the mechanical properties of copper at working temperature (823 K), silicon carbide fibres with a diameter of 140 mu m are used to reinforce the interface area between the plasma-facing material and the heat sink. Push-out tests show that the adhesion between SiC fibre and Cu matrix without any interlayer is very low. To increase the fibre-matrix bonding the fibres are coated with Cr and W with a thickness of 300-400 nm before Cu deposition by magnetron sputtering. Push-out tests on these modified fibres show a significant increase in adhesion compared to the fibres without interlayer. XRD investigations after a heat treatment at 923 K show a chromium carbide (Cr23C6, Cr3C2) formation and the absence of chromium silicides. In the case of a W interlayer a W2C formation is detected and also no tungsten silicides. Single-fibre tensile tests were performed to investigate the influence of the reaction zone on the ultimate tensile strength of the fibres. The ultimate tensile strength for fibres without interlayer remains constant at about 2200 MPa after annealing at 923 K. The fibres with chromium and tungsten interlayers, respectively, show a decrease of about 30% of the ultimate tensile strength after the heat treatment at 923 K. (C) 2007 Elsevier B.V. All rights reserved.