An experimental investigation on the W-Cu composites
An experimental investigation on the W-Cu composites
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DOI：
10.1016/j.matdes.2008.06.068
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发表时间：
2009-04-01
影响因子：
8.4
通讯作者：
Hegazy, A. Abousree
中科院分区：
文献类型：
--
作者：
Ibrahim, A.;Abdallah, M.;Hegazy, A. Abousree
近年来，钨铜净形状的制造已成为一个重要问题，因为其独特的性能使其适用于多种应用。在这项研究中，使用两种类型的制备粉末（即镀铜钨和元素粉末的混合物）通过粉末冶金技术加工含有 20 wt.% 和 30 wt.% Cu 的 W-Cu 复合粉末。钨粉的涂覆方法采用化学镀技术。将所研究的粉末在1250℃和1400℃两个烧结温度下进行冷压和真空烧结。结果表明，对于每种铜含量和压制压力，涂覆铜的压坯比混合的压坯具有更高的相对生坯密度，这意味着涂覆的粉末比未涂覆的粉末具有更大的压缩率。相对生坯密度随着压实压力和铜含量的增加而增加。烧结后，由未涂覆粉末制成的复合材料由于形成了大的铜和钨团聚体而表现出不均匀的结构，而涂覆钨复合材料的结构表明铜存在于钨晶粒内，形成均匀的互连结构。一般来说，由镀铜钨粉制成的复合材料比由混合元素粉末制成的复合材料表现出更高的密度、硬度、压缩强度和导电率。然而，镀铜复合材料的热膨胀系数和电阻率显示出较低的值。 (C) 2008 Elsevier Ltd. 保留所有权利。
Fabrication of tungsten-copper net-shapes has become an important issue in recent years due to their unique properties which make them suitable for a wide variety of applications. In this investigation, W-Cu composite powders containing 20 wt.% and 30 wt.% Cu were processed by powder metallurgy technique using two types of prepared powders, namely, Cu-coated tungsten and mixtures of elemental powders. The coating method of tungsten powders was carried out using electroless coating technique. The investigated powders were cold compacted and sintered in vacuum at two sintering temperatures, 1250 degrees C and 1400 degrees C.The results show that the Cu-coated compacts have higher relative green densities than those of admixed ones for each copper content and compaction pressure, which means that the coated powders have greater compressibility than the uncoated ones. The relative green density increases with increasing compaction pressure and copper content. After sintering, the composites fabricated from uncoated powders show inhomogeneous structure due to formation of large globules of copper and tungsten agglomerates, while the structure of coated tungsten composites reveals the existence of copper within the tungsten grains, forming uniform interconnected structure. In general, composites made from Cu-coated tungsten powders exhibited higher density, hardness, compression strength, and electrical conductivity than those of composites made from admixed elemental powders. However, coefficient of thermal expansion and electrical resistivity of Cu-coated composites showed lower values. (C) 2008 Elsevier Ltd. All rights reserved.