A Comparative Assessment of Explosive and Other Methods of Compaction in the Production of Tungsten—Copper Composites
A Comparative Assessment of Explosive and Other Methods of Compaction in the Production of Tungsten—Copper Composites
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DOI：
10.1179/pom.1976.19.1.31
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发表时间：
1976-01
影响因子：
1.4
通讯作者：
A. Bhalla;J. Williams
中科院分区：
文献类型：
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作者：
A. Bhalla;J. Williams
在通过压制和烧结混合粉末然后进行热加工或通过液相渗透技术来生产钨-铜复合材料时，在获得完全致密的材料方面出现了困难，特别是在钨含量为70wt；%时。采用液相烧结、热锻造、三轴压实、等静压和爆炸压实等方法制备了W含量在70~90wt%之间的W-Cu复合材料，并对其力学性能和电学性能进行了对比评价。在W含量为70wt.-%的情况下，研究表明，在1753K以下通过液态烧结获得的最大密度随着铜颗粒尺寸的减小而增加。使用−350目铜粉可获得95.5%的理论密度。在1·4 Gpa等静压条件下，无论初始铜颗粒尺寸如何，液态烧结复合材料的最大密度均为理论密度的95·5%。发现混合粉末的三轴压制是不合适的，因为观察到了压坯的断裂。在1173K以下热锻造烧结体，可获得99%的理论密度(T.D.)。当W含量增加到80wt.-%时，复合材料的密度达到最大值，达到90%T.D.，复合材料发生断裂。采用直接爆炸压实技术，使W含量高达90wt-%的复合材料可压制到97.8T.D。一般来说，尽管爆炸压实复合材料的硬度高于类似密度的热锻复合材料，但随着最终密度的增加，复合材料的硬度也随之增加。给定组合物的电导率是相当恒定的，无论生产方法如何，只要在复压或爆炸压实后进行退火热处理。
In the production of tungsten-copper composites by pressing and sintering mixed powders followed by hot working, or by liquid-phase infiltration techniques, difficulties arise in obtaining a fully dense material, particularly at tungsten contents > 70 wt.-%. W–Cu composites containing between 70 and 90 wt.-% W have been made by various routes including liquid-phase sintering, hot forging, triaxial compaction, isostatic re-pressing, and explosive compaction, and a comparative assessment of their mechanical and electrical properties has been made. In the case of composites containing 70 wt.-% W, it has been shown that the maximum density achieved by liquid-phase sintering at up to 1753 K increases as the Cu particle size decreases. A density of 95·5% theoretical was obtained using −350 mesh Cu powder. Isostatic repressing at 1·4 GPa of liquid-phase sintered composites yielded a maximum density of 95·5% theoretical, irrespective of initial Cu particle size. Triaxial compaction of the mixed powders was found to be unsuitable in that fracturing of the compact was observed. Hot forging of sintered compacts at up to 1173 K yielded a product of 99% theoretical density (T.D.) in the 70/30 composition, whereas when the W content was raised to 80 wt.-%, a maximum density of 90% T.D. was attained, with fracturing of the composite. The use of the direct explosive-compaction technique has enabled composites with up to 90 wt.-% W to be compacted to 97·8% T.D. In general, the hardness of the composites increased with increasing final density, although explosively compacted composites had higher hardness values than hot-forged composites of similar density. The electrical conductivity for a given composition was fairly constant irrespective of method of production, provided that an annealing treatment was given after re-pressing or explosive compacting.