中文摘要：

利用扫描电镜（SEM）、透射电镜（TEM）和示差扫描量热法（DSC）研究了4．4％TiCp／7075Al基复合材料的二次加热组织演变规律及其影响因素．结果表明：4．4％TiCp／7075Al基复合材料的最佳二次加热工艺参数是加热温度为590～610℃，保温时间为10～20min；4．4％TiCp／7075Al基复合材料在二次加热过程中具有较高的稳定性，随温度的升高和保温时间的延长，球形晶粒尺寸增加较小；4．4％TiCp／7075Al基复合材料在600℃时的晶粒粗化速率常数为118．96μm·s^-1，远小于7075基体合金的晶粒粗化速率常数311．7μm^3·s^-1更加适宜于半固态触变成形．

英文摘要：

The reheated microstructures and influencing factors of semi-solid ingots of 4.4 % TiCp/7075 composites were investigated by SEM, TEM and DSC. The results show that the optimal remehed parameters of 4.4 % TiCp/7075 composites are the remolded temperature of 590 to 610 ℃ and the holding time of 10 to 20 min. 4.4 % TiCp/7075 composites are of high stability during the remelting process and the size of spherical grains can hardly increase with the increase of temperature and holding time. The coarsening velocity of grains in 4.4 % TiCp/7075 is 118.96μm^3·s^- 1, which is less than 311.7 μm^3· s^- 1 for 7075 matrix alloy, and more suitable for semi-solid thixoforming.