摘要
采用原位合成技术成功制备了Ag/Y2O3和Ag/CeO2电接触材料。X射线衍射分析表明反应合成材料中的相是Ag和Y2O3,CeO2;BSE图像显示:稀土氧化物在基体中呈球状弥散分布,粒径约为0.1μm^0.4μm,界面清洁,内氧化层与基体结合良好,改善了增强相与基体浸润不良的问题,并使材料致密度得到提高。测量材料的物理性能和力学性能,发现2种氧化物对基体的影响基本趋于一致。分析氧化物的原位形核机制,认为是氧在基体金属中通过克服原子间势垒扩散进入合金内部,发生择优氧化。扩散的主要方式是体扩散,生成的增强相牢固地嵌入基体,使得该复合材料的界面结合紧,综合性能优良。
The electric contact materials of Ag/CeO2 and Ag/Y2O3 were successfully synthesized by in situ（reactive synthesis） process .It is clearly showed that three phases coexisted in the matrix, Ag, Y2O3 and CeO2： The spherical oxides particles of the rare-earth elements dispersed homogenously in the matrix, the diameters of these particles ranged from 0.1 μm-0.4 μm with clean surface and the internally oxidized layer was bounded tightly with the matrix, resulting in improving the wettability between reinforced phases and the matiris, increasing the desity, The influences of the two oxides particles on the matrix became basically equal according to determining current resistivity and micro hardness. The nucleation mechanism of oxide particles prepared by in situ process was discussed. It is suggested that the oxygen atoms with higher energy can be diffused into the matrix freely and react immediately. Many parameters will affect this process, such as radius and properties of the matrix elements, reaction temperature and the holding time. Because oxygen atoms diffused into the matrix predominantly through sintered bodies, the oxide particles of rare-earth elements dispersed well and was bounded tightly with matrix elements. Reaction temperature, amount of oxygen supply, pressure for working holding time and partial pressure of oxygen are the main parameters which could affect the reactive synthesis.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2007年第1期174-177,共4页
Rare Metal Materials and Engineering
基金
国家科技攻关项目(2001BA326C)
云南省科技攻关项目(2000B-03)资助
关键词
银稀土合金
反应合成
Ag/RExOy
内氧化
电接触材料
sliver-rare earth alloys
reactive synthesis
Ag/RExOy
internal oxidation
electric contact materials
