Phase formation process of bulk MgB2 analyzed by Differential Thermal Analysis during sintering
Phase formation process of bulk MgB2 analyzed by Differential Thermal Analysis during sintering
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DOI：
10.1016/j.jallcom.2007.04.045
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发表时间：
2008-06
影响因子：
6.2
通讯作者：
Q. Shi;Y. Liu;Qian Zhao;Zongqing Ma
中科院分区：
文献类型：
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作者：
Q. Shi;Y. Liu;Qian Zhao;Zongqing Ma
为了弄清块体MgB 2相的反应过程，以差热分析（DTA）为主要手段制备了块体MgB 2样品，并对烧结反应过程进行了监测。结合SEM和X射线衍射分析，总结了MgB 2相的形成过程。Mg和B粉末之间的反应在纯Mg的熔点之前开始。MgB 2的形成过程分为两个不同阶段：（1）固-固反应阶段，Mg和B粉不能完全反应，气孔的钉扎作用限制MgB 2晶粒的生长;（2）固-液反应阶段，熔融Mg促进反应过程，通过溶解-再沉淀和生长形成规则六边形块状MgB 2晶粒。
In order to clarify the reaction process of bulk MgB2phase, Differential Thermal Analysis (DTA), as the main measurement, was used to prepare bulk MgB2samples and monitor the sintering reaction process. Combined with microstructure observation by SEM and X-ray diffraction analysis, the formation process of MgB2phase was summarized. The reaction between Mg and B powders onsets before the melting point of pure Mg. The whole formation process of MgB2includes two different stages: (1) solid–solid reaction stage, in which Mg and B powder cannot react completely and the growth of MgB2grain is restricted by the pinning effects of pore; (2) solid–liquid reaction stage, in which the fused Mg promotes the reaction process and the regular hexagon bulky MgB2grain forms by means of solution-reprecipitation and growth.