摘要
分别采用相同纯度(99.9%)和粒度(<45μm)的球形和屑状Mg粉与无定形B粉,按照MgB2化学计量比均匀混合后,在10MPa的压力下压制成块。并在650,700,750,800和850℃温度下进行固态烧结反应制备了MgB2块材。采用浸入介质法测量MgB2块材的孔隙特征参数。结果表明,两类试样的孔隙率相近,并且都随烧结温度的升高而增大。扫描电镜分析显示,试样内的孔洞形状和尺寸与初始Mg粉的形状和尺寸紧密相关。基于Mg-B体系的反应模型,对该体系烧结过程中孔洞形成原因进行了分析。
The MgB2 bulks were prepared using the spherical and scrap-like magnesium powders with the same purity （99.9%） and grain size （〈45 μm） as raw materials. The two kinds of magnesium powder were mixed with amorphous boron powder with a nominal stoichiometry of MgB2, then pressed into pellets under a pressure of 10 MPa, and sintered at 650 ℃, 700 ℃, 750 ℃ and 800 ℃, respectively. The characteristics of holes for the sintered samples were described by using the immerged medium method. The results indicate that the porosities in the two kinds of MgB2 samples are similar. Their porosities increase with the increase of sintering temperature. The scanning electron microscope observation shows that the shapes and sizes of holes in sintered sample are associated with those of the raw Mg powder. Finally, the reason of hole formation for the Mg-B system during sintering process was analyzed based on the reaction model of Mg-B system.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第7期1260-1262,共3页
Rare Metal Materials and Engineering
基金
国家自然科学基金项目(50472099)
国家重点基础项目研究发展计划(2006CB601004)
西北工业大学博士论文创新基金资助
