Al-Li合金中缺陷和电子密度的正电子寿命谱  

A POSITRON ANNIHILATION LIFETIME OF DEFECT AND ELECTRONIC DENSITY OF Al Li BASED ALLOYS

作　　者：吴伟明[1] 高英俊[1] 邓文[1] 罗里熊[1] 许少杰[1] 钟夏平[1] 蒋晓军[2] 

机构地区：[1]广西大学物理系 [2]中国科学院金属研究所

出　　处：《中国有色金属学报》1997年第4期123-126,共4页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金

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。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 condi tions 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.

关 键 词：正电子寿命谱 缺陷 铝合金 电子密度 

分 类 号：TG146.21[一般工业技术—材料科学与工程]