Mechanism and kinetics of bubble formation in doped tungsten
Mechanism and kinetics of bubble formation in doped tungsten
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DOI：
10.1007/bf02917539
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发表时间：
1971
期刊：
影响因子：
--
通讯作者：
D. Moon;R. Koo
中科院分区：
文献类型：
--
作者：
D. Moon;R. Koo
用电子显微镜研究了掺杂少量K、Al和Si化合物的钨在退火过程中气泡形成的机理和动力学。由于烧结处理过程中掺杂物的挥发，在烧结钢锭中存在气泡。当钢锭被加工成金属丝时，存在于钢锭中的气泡被拉长。在退火过程中，这些拉长的气泡会发生形状变化，这取决于加工的量。长宽比小于10的细长气泡会球化，而长宽比大于20的气泡则不稳定，会破裂成一排气泡。如果工作已经足够关闭拉长的气泡，例如。在由0.9 mm直径的丝卷成的0.125 mm厚的带状材料中，由于空穴向挥发性掺杂颗粒的扩散而形成气泡。
The mechanisms and kinetics of bubble formation that occur during annealing of tungsten doped with small amounts of K, Al, and Si compounds has been investigated by electron microscopy. Bubbles are present in the sintered ingot due to volatilization of the dope during the sintering treatment. As the ingot is worked down into wire, the bubbles present in the ingot become elongated. On annealing these elongated bubbles undergo shape changes which depend on the amount of working. Elongated bubbles with a length-to-width ratio of less than ten spheroidized while those with a length-to-width ratio greater than twenty are unstable and break up into a row of bubbles. If working has been sufficient to close up the elongated bubbles,e.g., in ribbon, 0.125 mm thick rolled from 0.9 mm diam wire, bubble formation results from the diffusion of vacancies to the volatile dopant particles.