液态浸渗后直接挤压铝基复合材料的组织特征

Microstructure Features of Al_2O_3sf/Al Composites Infiltrated Liquidly and Extruded Directly

实验研究了液态浸渗后直接挤压工艺制备的氧化铝短纤维增强铝基复合材料（Ａｌ２Ｏ３ｓｆ／Ａｌ）的组织。发现其主要组织特征为：基体致密，为均匀细小的变形再结晶组织；纤维分布均匀，不存在相互搭桥、缠结和成束聚集现象；纤维保留了较大的长径比，其平均长径比大于临界长径比，能起到较好的增强承载作用。表明液态浸渗后直接挤压工艺具有消除缺陷、强化基体、改善纤维分布并避免纤维在成形过程中的破断与损伤等诸多优点。

The microstructure of Al-base composites reinforced by Al2O3 short fiber (Al2O3sf/Al), manufactrued by a technique of infiltrating liquidly and extruding directly, was investigated. The mi crostructure features of the composites lie mainly in the dense matrix (uniform and fine grains deformed and recrystallized), the fiber well-distributed,(no-bridging no-tangling and no-bunching), the high as pect ratio of fiber (with the average higher than the critical) and a good reinforcing effect. The results show that this technique has many advantages such as eliminating defects, reinforcing matrix, improving fiber distribution and preventing fracture and injure of the fiber.