(1. 燕山大学 机械工程学院，秦皇岛 066004；
2. 燕山大学 材料科学与工程学院，秦皇岛 066004；
3. 中南大学 高性能复杂制造国家重点实验室，长沙 410083)
摘 要: 为解决大型铝合金航空结构件在传统热模锻工艺下出现的表层心部组织不均匀问题，采用低温小变形工艺对锻件的组织均匀性进行调控。利用热/力模拟实验机、电子背散射衍射、透射电子显微镜等实验手段研究低温小变形工艺对高强铝合金锻件晶粒组织演变的影响规律。结果表明：随着变形温度的升高，锻件的动态回复加剧，小角度晶界含量先增加后减少，位错形态经历位错缠结、位错胞，以及位错胞合并长大形成亚晶的过程。经过变形温度为200 ℃、变形量为20%的低温小变形及固溶处理后，锻件表层晶粒得到了有效细化。最终，获得高强铝合金锻件组织均匀性的低温小变形调控新方法。
关键字: 低温小变形；静态再结晶；位错形态；组织均匀性
（1. School of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China;
2. School of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004, China;
3. State Key Laboratory of High Perfermance Complex Manufacturing, Central South University, Changsha 410083, China）
Abstract:In order to solve the problem of uneven surface structure in the center of large aluminum alloy aviation structure parts under the traditional hot die forging process, the low temperature small deformation process was used to control the microstructure uniformity of the forging. The effects of microstructure homogeneity regulation were investigated by means of thermal/force simulation machine, electron backscatter diffraction and transmission electron microscopy. The results show that with the increase of deformation temperature, the dynamic recovery of forging is intensified and the content of small-angle grain boundary increases and then decline. The dislocation morphology of aluminum forging changes from dislocation entanglement to dislocation cell, and gradually turns into subgrain. After the small deformation process and solution treatment at a deformation temperature of 200 ℃ and a deformation of 20%, the surface grains of the forging are effectively refined. Finally, the novel method is obtained for the microstructure homogeneity regulation of high strength aluminum forging.
Key words: small deformation process at low temperature; static recrystallization; dislocation morphology; microstructure uniformity
