原位法低温合成MgB2的孔隙形成机制  

The Mechanism of Pore Formation in Superconducting MgB_2 Synthesized at Low Temperature by In-Situ Process

作　　者：吴怡芳[1] 闫果[1] 闫世成[1] 李成山[1] 李金山[2] 卢亚锋[1] 

机构地区：[1]西北有色金属研究院,陕西西安710016 [2]西北工业大学,陕西西安710072

出　　处：《稀有金属材料与工程》2009年第4期647-650,共4页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50672077);国家“973”计划(2006CB601004);陕西省自然科学基金(2006E101)

摘　　要：采用XRD、SEM、DSC等分析测试方法,研究原位法低温合成MgB2的孔隙形成机制。结果表明,高能球磨后B小颗粒镶嵌在Mg大颗粒上,热处理时MgB2相首先在Mg、B的镶嵌区域生成。MgB2相生成过程中,闭孔隙主要是由Kirkendall效应造成的,开孔隙形成的主要原因是Mg气化后与B反应形成了与环境保持连通的孔隙。Using X-ray diffraction （XRD）, scanning electron microscopy （SEM） and differential scanning calorimetry （DSC） the mechanism of pore formation of superconducting MgB2 synthesized at low temperature by in-situ process was studied. It is showed that B powder was embedded into Mg powder after the ball-milling process. MgB2 phase formed firstly in these embedded areas. The closed pores in MgB2 bulks are caused by kirkendall effect due to the different diffusion speeds of Mg and B atoms. The open pores are caused by Mg gas.

关 键 词：MGB2 孔隙 球磨 超导 

分 类 号：TB303[一般工业技术—材料科学与工程]