Cu Al混合粉经过球磨后的^(27)Al核磁共振谱与机械合金化反应  

^(27)Al NUCLEAR MAGNETIC RESONANCE ANALYSIS OF MECHANICAL ALLOYING PROCESS IN Cu\|Al MIXED POWDERS 

作　　者：李百秦[1] 聂矗[1] 

机构地区：[1]南京大学固体微结构物理国家重点实验室,南京大学物理系南京210093

出　　处：《物理学报》2000年第1期155-159,共5页Acta Physica Sinica

基　　金：教育部留学回国人员科研启动基金

摘　　要：测量了ＣｕＡｌ 混合粉末经过不同时间球磨后的２７Ａｌ 核磁共振（ＮＭＲ） 谱，分析了２７Ａｌ ＮＭＲ 谱的特征参量随球磨时间的变化．根据２７Ａｌ ＮＭＲ 谱所提供的信息，研究了ＣｕＡｌ 混合粉末机械合金化反应的微观过程．ＣｕＡｌ 混合粉末的２７Ａｌ Ｋｎｉｇｈｔ 位移随球磨时间的增加而减小．对于ＣｕＡｌ 混合粉末，球磨不仅改变了２７Ａｌ 附近的化学短程序，而且也直接地影响了２７Ａｌ 的外层电子态，后者使传导电子的ｓ 态成分减小．实验结果表明，ＣｕＡｌ 混合粉末在球磨过程中发生了真正的合金化反应；经过９０ ｈ 球磨完成了合金化反应；用机械合金化法制备的ＣｕＡｌThe variations of the \{\}\+\{27\}Al nuclear magnetic resonance (NMR) spectra of the aluminum\|copper powder mixtures after different time of ball milling have been measured.By analyzing the \{\}\+\{27\}Al NMR spectra,the mechanical alloying (MA) process has been investigated at microscopic level.\{\}\+\{27\}Al Knight shifts in the series of Cu\|Al samples decrease with increasing time of ball\|milling.This means that the s component in the states of valence electron declines.The experimental results indicate that the ture alloying reaction takes place during the MA process,and it is complete after about 90 hours of ball milling under our mechanical alloying conditions.Compared with the early results of \{\}\+\{27\}Al Knight shifts measured in the samples prepared by the traditional melt\|alloying method,it has been concluded that the real Cu\|Al alloys can be obtained by MA process,and they possess the same chemical short\|ranged order as those with the same ingredients obtained by melting.

关 键 词：铜-铝混合粉 铝27 核磁共振谱 机械合金化 

分 类 号：TG146.11[一般工业技术—材料科学与工程]