Zhou Z., Fan Z., Peng H. X., Li D. X.
Laboratory of Atomic Imaging of Solids, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, P. R. China; Department of Materials Engineering, Brunel University, Uxbridge, U.K.
J Microsc. 2001 Feb;201(2):144-152. doi: 10.1046/j.1365-2818.2001.00834.x.
High-resolution electron microscopy was employed to characterize the interface structure of a cast Al-Mg-Si-Bi-Pb aluminium(6262)-based composite reinforced by alpha alumina particles with a trace of beta alumina in order to investigate the behaviour of alloying elements in cast composites. Except for a few primary Mg2Si particles, few reaction products were detected at the interface of Al/alpha-Al2O3 due to the unfavourable reaction kinetics during the squeeze-casting process. The Mg2Si particle has an orientation relationship with alpha-Al2O3 of [011]Mg2Si//[1210]alpha-Al2O3 (111)Mg2Si//(0006)alpha-Al2O3. A significant amount of MgAl2O4 was found on the surface of the beta-Al2O3 particles, which is in contrast to the small degree of reaction found on alpha-Al2O3 particles. MgAl2O4 and beta-Al2O3 particles have the following orientation relationship: [011]MgAl2O4//[1210]beta-Al2O3 (111) MgAl2O4//(0006)beta-Al2O3. The similar crystal structure of beta-Al2O3 to MgAl2O4 favours MgAl2O4 nucleation and growth on the surface of beta-Al2O3. Interfacial energy minimization dominates the atomic structure of the interface with the result that close packed planes and directions in the Al2O3 reinforcement and reaction products are parallel to the interfaces. Bi and Pb were found in the form of metallic nanometre particles between Al2O3 particles, or between the MgAl2O4 and Al2O3 particles, or in the open channels of beta-Al2O3 filled by the Al matrix.
采用高分辨率电子显微镜对铸态Al-Mg-Si-Bi-Pb铝基（6262）复合材料的界面结构进行表征，该复合材料由α氧化铝颗粒增强，并含有微量β氧化铝，以研究铸态复合材料中合金元素的行为。除了少数初生Mg2Si颗粒外，由于挤压铸造过程中不利的反应动力学，在Al/α-Al2O3界面处几乎未检测到反应产物。Mg2Si颗粒与α-Al2O3具有[011]Mg2Si//[1210]α-Al2O3（111）Mg2Si//（0006）α-Al2O3的取向关系。在β-Al2O3颗粒表面发现了大量的MgAl2O4，这与在α-Al2O3颗粒上发现的少量反应形成对比。MgAl2O4和β-Al2O3颗粒具有以下取向关系：[011]MgAl2O4//[1210]β-Al2O3（111）MgAl2O4//（0006）β-Al2O3。β-Al2O3与MgAl2O4相似的晶体结构有利于MgAl2O4在β-Al2O3表面形核和生长。界面能最小化主导了界面的原子结构，结果是Al2O3增强体和反应产物中的密排面和方向与界面平行。在Al2O3颗粒之间、MgAl2O4与Al2O3颗粒之间或由Al基体填充的β-Al2O3的开放通道中发现了Bi和Pb以金属纳米颗粒的形式存在。
