【摘要】 通过XD(ExothermicDispersion)法原位反应生成Al2 O3 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 10 73K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Al2 O3 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合成的主要因素更多还原

【Abstract】 Al 2O 3 and Al 3Ti 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 TiO 2 system can be reacted in very short time. The reaction is propagated in combustion wave. It is also shown that aluminum initially react with TiO 2 to form Al 2O 3 and reduced Ti by X ray diffraction and scanning electroric microscopy. Then the reaction between reduced Ti and aluminum is subsequently followed. The Al 2O 3 and Al 3Ti 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 TiO 2 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.更多还原