(1. 东南大学 材料系， 南京 210096；
2. 南京理工大学 材料系， 南京 210094)
摘 要: 通过XD(Exothermic Dispersion)法原位反应生成Al2O3与Al3Ti复合增强的铝基复合材料，结果表明Al/TiO2经充分混合、挤压成坯后，在真空炉中以一定的升温速率加热至1 073 K左右时发生剧烈的化学反应。由SEM，XRD及能谱分析可知：生成物Al2O3呈等轴颗粒状，Al3Ti呈棒状。主要分析了反应过程的热力学并简要说明了影响XD合成的主要因素。
关键字:
exothemic dispersion synthesis technology
（1. Department of Materials Science and Engineering,
South East University, Nanjing 210096, P.R.China；
2. Department of Materials Science and Engineering,
Nanjing University of Science and Technology, Nanjing 210094, P.R.China）
Abstract:Al2O3 and Al3Ti reinforced aluminum matrix composites were prepared by means of exothermic dispersion (XD) in-situ synthesis technique. Its kinetic mechanism was also discussed. The results show that Al-TiO2 system can be reacted in very short time. The reaction is propagated in combustion wave. It is also shown that aluminum initially react with TiO2 to form Al2O3 and reduced Ti by X-ray diffraction and scanning electroric microscopy. Then the reaction between reduced Ti and aluminum is subsequently followed. The Al2O3 and Al3Ti take the shapes of equiaxed particle and block respectively. A certain heating rate and content of aluminum are needed，if thermal explosion occurs commonly in the Al-TiO2 system. The aluminum content and green density also have influences on the combustion temperature and bulk shrinkage. The combustion temperature would be lower for higher aluminum content, but its bulk shrinkage would be higher.
Key words: in-situ chemical reaction； thermodynamic； combustion wave； aluminum matrix composites
