Al-Li合金中缺陷和电子密度的正电子寿命谱

来源期刊：中国有色金属学报1997年第4期

论文作者：吴伟明 高英俊 邓文 罗里熊 许少杰 钟夏平 蒋晓军

文章页码：123 - 126

关键词：深低温 正电子寿命谱 Al-Li-Cu-Mg-Zr合金 缺陷

Key words：cryogenic temperature positron lifetime spectrum Al-Li-Cu-Mg-Zr alloy defects

摘    要：在深低温到室温不同温度下，测量了不同时效状态的Al-Li-Cu-Mg-Zr合金和含Zn 、Ag或Sc的合金的正电子寿命谱。分析表明：峰值时效使热空位大量回复并使基体电子密度提高。在深低温下，空位主要以单空位形式存在且随温度升高而激活并运动复合成多空位。Zn和Ag对空位的运动有束缚作用，Sc有助于空位的运动。样品在低温下基体电子密度升高，对合金低温强度产生重要影响。

Abstract: At the variant points from cryogenic to ambient temperature, the positron annihilation lifetime spectra of Al-Li-Cu-Mg-Zr alloy added with or no Zn, Ag, Sc at different ageing conditions were measured. The analyses for lifetime spectra show that a large number of thermal vacancies are recovered and the bulk electronic density increases during the peak-ageing process. At the cryogenic temperature the vacancies are mainly monovacancies, while with the temperature increasing they become activated and move to combine into multivacancies. The doping of Zn or Ag will hinder the movement of monovacancies but that of Sc is available to the movement. The bulk electronic density in all samples at low temperature is higher than that at ambient temperature, which has important influence on the low temperature strength of alloys.