【摘要】 为了研究AlCuFe准晶体的形成机理,采用了X射线衍射(XRD)和扩展X射线吸收精细结构(EX-AFS)2种分析技术,有效地克服了高度无序体系结构分析的困难。研究结果表明,在球磨过程中Cu原子进入Al的晶格点阵,经过不同球磨时间分别形成金属间化合物Al2Cu或者Cu9Al4,而Fe原子保持原来的体心立方(bcc)α-Fe结构不变;退火处理可以驱使α-Fe与Al和Al-Cu化合物反应,主要的产物分别为Al7Cu2Fe化合物或者Al(Cu,Fe)固溶体;最后,在较高的温度下Al7Cu2Fe转变为Al65Cu20Fe15准晶体。更多还原

【Abstract】 To study the mechanism of AlCuFe quasicrystalline(QC) formation,the x-ray diffraction(XRD) and x-ray absorption fine structure(XAFS) were adopted.The combination of both the methods successfully overcame the difficulties in the analysis of the highly disordered structures.The results indicate that during the milling process,only Cu can incorporate into the lattice of Al to form an Al2Cu or Cu9Al4,which depends on the milling times.Fe remains the original structure of bcc α-Fe.However,annealing can drive the α-Fe to react with Al and Al-Cu compounds.The main products are Al7Cu2Fe compound or Al(Cu,Fe) solid solution,respectively.Then at higher temperature the Al7Cu2Fe transforms into the icosahedral Al65Cu20Fe15 quasicrystal.更多还原