(1. 燕山大學 機械工程學院，秦皇島 066004；
2. 燕山大學 材料科學與工程學院，秦皇島 066004；
3. 中南大學 高性能復雜制造國家重點實驗室，長沙 410083)
摘 要: 為解決大型鋁合金航空結構件在傳統(tǒng)熱模鍛工藝下出現(xiàn)的表層心部組織不均勻問題，采用低溫小變形工藝對鍛件的組織均勻性進行調(diào)控。利用熱/力模擬實驗機、電子背散射衍射、透射電子顯微鏡等實驗手段研究低溫小變形工藝對高強鋁合金鍛件晶粒組織演變的影響規(guī)律。結果表明：隨著變形溫度的升高，鍛件的動態(tài)回復加劇，小角度晶界含量先增加后減少，位錯形態(tài)經(jīng)歷位錯纏結、位錯胞，以及位錯胞合并長大形成亞晶的過程。經(jīng)過變形溫度為200 ℃、變形量為20%的低溫小變形及固溶處理后，鍛件表層晶粒得到了有效細化。最終，獲得高強鋁合金鍛件組織均勻性的低溫小變形調(diào)控新方法。
關鍵字: 低溫小變形；靜態(tài)再結晶；位錯形態(tài)；組織均勻性
（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
