复合材料的界面结构
(1. 南京理工大学 材料科学与工程系，南京 210094；
2. 东南大学 材料科学与工程系， 南京 210096)
摘 要: 借助于SEM和TEM研究了Al-TiO2-B2O3系热扩散反应法合成铝基复合材料的界面结构。结果表明： 在B2O3与TiO2摩尔比小于1时， 增强相由棒状的Al3Ti及颗粒状的TiB2和α-Al2O3组成。 Al3Ti与基体的界面干净、 相容性好， 在基体中分布均匀； TiB2与铝基体界面干净， 并存在以下位向关系： [(-)23(-)1]Al∥ [0001]TiB2, (204[TX-])Al∥（(-)24(-)20）TiB2 ，可成为基体结晶时的核心， 细化基体晶粒； α-Al2O3与铝基体的润湿性差，被推挤到基体颗粒的界面呈偏聚状态， 并存有孪晶现象， 其孪晶面为（111）， 孪生方向为［11(-)2] ］。
关键字: 热扩散反应; 界面结构; 铝基复合材料; 位向关系; 偏聚
TiB2/Al composites fabricated by exothermic dispersion reaction method
（ 1. Department of Materials Science and Engineering,
Nanjing University of Science and Technology, Najing 210094, China;
2. Department of Materials Science and Engineering,
Southeast University, Nanjing 210096, China）
Abstract: The interface structure of aluminum matrix composites fabricated by exothermic dispersion reaction method in Al-TiO2-B2O3 reaction system was investigated by using of scanning electron microscope and transmitted electron microscope. The results show that the reinforcements of the composites are consisted of α-Al2O3, TiB2 and Al-3Ti when the B2O3/TiO2 mole ratio of B2O3 to TiO2 is less than 1. Al3Ti phase in stick shape has clean interface and good crystallographic relationship with aluminum matrix. TiB2 phase also has crystallographic orientation relationships with matrix, that are ［(-)23(-)1］Al//［0001］TiB2 and (20(-)4)Al((-)24(-)20)TiB2, and they can be able to become the crystalline nucleuses of the matrix during consideration, which results in refining the aluminum matrix. At the same time, the α-Al2O3 reinforcement phase with grain shape segregates at grain boundaries of the matrix due to its bad wetting with the aluminum matrix. There are twin grain phenomenon in some α-Al2O3 particulates. The twin plane and direction are （111） and ［11(-)2］ respectively.
Key words: exothermic dispersion reaction(XD); interface structure; aluminum matrix composites; orientation relationship; segregation
