Fabrication of Al2O3-W Functionally Graded Materials by Slipcasting Method
Fabrication of Al2O3-W Functionally Graded Materials by Slipcasting Method
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注浆成型法制备Al2O3-W功能梯度材料
DOI：
10.1088/1757-899x/18/20/202023
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
K. Nakashima
中科院分区：
文献类型：
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作者：
T. Katayama;Sohei Sukenaga;N. Saito;Hajime Kagata;K. Nakashima
本文采用注浆成型法成功地制备了一种由钨粉和氧化铝粉组成的功能梯度材料。这种FGM可用作具有半透明氧化铝外壳的高强度放电灯（HiDL）的密封和导电组件。两种类型的W粉，具有不同的氧化性能，被用作Al 2 O3-W功能梯度材料的原料粉末。通过在空气中在200 °C下热处理180分钟来制备“氧化W”。在超纯水中通过超声波搅拌混合氧化铝和各W粉末。然后在受控压力下将浆料浇铸到具有多孔氧化铝基底的圆柱形丙烯酸模具中。随后干燥绿色压坯，然后使用真空炉在1600 °C下烧结固定时间。利用扫描电子显微镜（SEM）观察了功能梯度材料的微观结构。具有“氧化W”粉末的Al 2 O3-W FGM导致微观组成梯度。然而，与“收到的W”的FGM没有表现出成分梯度。这主要归因于不同氧化条件下W粉的氧化电位不同，基本上“氧化W”粉倾向于分散，因为包覆在W粉芯上的氧化层的氧化电位较大。
We have successfully fabricated a functionally graded material (FGM) from tungsten and alumina powders by a slip-casting method. This FGM has applications as a sealing and conducting component for high-intensity discharge lamps (HiDLs) that have a translucent alumina envelope. Two types of W powder, with different oxidizing properties, were used as the raw powders for the Al2O3–W FGM. "Oxidized W" was prepared by heat-treatment at 200 °C for 180 min in air. Alumina and each of the W powders were mixed in ultrapure water by ultrasonic stirring. The slurry was then cast into a cylindrical acrylic mold, which had a base of porous alumina, under controlled pressure. The green compacts were subsequently dried, and then sintered using a vacuum furnace at 1600 °C for a fixed time. The microstructures of the FGMs were observed by scanning electron microscopy (SEM) of the polished section. The Al2O3–W FGM with the "oxidized W" powder resulted in a microscopic compositional gradient. However, the FGM with "as-received W" showed no compositional gradient. This result was mainly attributed to the difference between the ζ-potentials of the W powders with the different oxidizing conditions; basically "oxidized W" powder tends to disperse because of the larger ζ-potential of the oxide layer coated on the W powder core.