Synthesis of molybdenum disilicide by mechanical alloying
Synthesis of molybdenum disilicide by mechanical alloying
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DOI：
10.1016/0921-5093(92)90314-q
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发表时间：
1992-06
期刊：
影响因子：
6.4
通讯作者：
R. Schwarz;S. Srinivasan;J. Petrovic;C. Maggiore
中科院分区：
文献类型：
--
作者：
R. Schwarz;S. Srinivasan;J. Petrovic;C. Maggiore
人们对开发低氧含量的二硅化钼（MoSi2）合金非常感兴趣和努力。在合金合成过程中，氧与Si结合，在mosi2晶界处形成玻璃状的sio2沉淀，导致其力学性能下降。从单质粉末开始，采用机械合金化高能球磨工艺合成了MoSi2、MoSi2- 27mol .% MoSi3、MoSi2- 50mol .% mo5si3和MoSi2- 50mol .% wsi2合金粉末。粉末的加工以及粉末在石墨模具中的装载是在手套箱内的高纯氩气下进行的。机械合金粉末的晶粒和粒度更细，使我们能够在1500°C下热压它们，这比目前用于热压商业粉末的温度低300°C。通过核（d,p）反应，我们已经成功地将合金中的氧含量降低到按重量计约310ppm。本文报道了机械合金粉末中亚稳相的形成及其x射线衍射和差热分析的表征。我们还报道了热压合金的光学和透射电子显微镜表征，以及高温力学性能的测量。
Considerable interest and effort are being directed towards developing molybdenum disilicide (MoSi2) alloys with low oxygen content. During alloy synthesis, oxygen combines with Si to form glassy SiO2precipitates at the MoSi2grain boundaries, resulting in a degradation of its mechanical properties. We have used mechanical alloying, a high-energy ball-milling process, to synthesize alloy powders of MoSi2, MoSi2-27 mol.% MoSi3, MoSi2-50 mol.% Mo5Si3and MoSi2-50 mol.% WSi2starting from elemental powders. The processing of the powders, as well as the loading of the powders in graphite dies, was performed under high-purity argon inside a glovebox. The finer grain and particle size of the mechanically alloyed powders enabled us to hot-press them at 1500 °C, which is 300 °C lower than the temperature currently used for hot-pressing commercial powders. We have been successful in reducing the oxygen content in our alloys to about 310 ppm by weight, as measured by nuclear (d,p) reactions. We report the formation of metastable phases in the mechanically alloyed powders and their characterization by X-ray diffraction and differential thermal analysis. We also report the characterization of the hot-pressed alloys by optical and transmission electron microscopy, and the measurement of high-temperature mechanical properties.