Fabrication of W-20 wt % Cu composite nanopowder and sintered alloy with high thermal conductivity
Fabrication of W-20 wt % Cu composite nanopowder and sintered alloy with high thermal conductivity
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DOI：
10.1016/s0167-577x(03)00071-5
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发表时间：
2003-05-01
影响因子：
3
通讯作者：
Kim, BK
中科院分区：
文献类型：
--
作者：
Hong, SH;Kim, BK
采用机械力-热化学法成功地合成了W颗粒尺寸在30~100 nm之间、成分分布均匀的W-20%Cu还原粉末。该工艺包括三个步骤：氧化物粉末的生产、氧化物粉末的湿法球磨和最终还原。采用喷雾干燥法制备了球壳结构的W/Cu复合氧化物团簇，然后在750℃下氧化2 h，经湿法球磨后在600~800℃的氢气中还原得到细小的氧化物微粉。研究了复合粉末的烧结行为和烧结合金的导热系数。与常规混合粉末相比，该复合粉末具有更高的烧结性。本工作制备的W-20%Cu合金的导热系数为239+/-5.0W/mK，与理论值相当。这种粉末的优良性能是由于粉末中纳米级的W和铜颗粒混合均匀，W固体粒子在液态铜中均匀分布，以及粉末的高纯度。该合金不含Fe、Co等传统工艺容易引入粉末中的杂质。(C)2003 Elsevier Science B.V.保留所有权利。
The reduced W-20% Cu powder with W particle sizes of about 30-100 nm and uniform distribution of components was successfully synthesized by mechano-thermochemical process. This process consists of three steps: the producing of oxide powder, the wet ball milling of oxide powder and the final reduction. W/Cu composite oxide clusters with a spherical shell structure were prepared by spray drying of aqueous solution of Cu and W salts with subsequent oxidation at 750degreesC for 2 h. These oxide clusters were fragmented to fine oxide powders by wet milling and reduced at 600-800degreesC in hydrogen. The sintering behavior of composite powder and thermal conductivity of sintered alloys were also investigated. This composite powder showed higher sinterability comparatively with conventional blended powders. The thermal conductivity of W-20% Cu alloys prepared by this work is 239+/-5.0 W/mK, which is equal to the theoretical value. Superior properties of the present powder are due to the homogeneous mixing state of natiosized W and Cu particles in powder, homogeneous redistribution of W solid particles in liquid Cu and high purity of powder. This alloy did not contain such impurities as Fe and Co that can be easily introduced in powder in conventional processing. (C) 2003 Elsevier Science B.V. All rights reserved.