(1. 东北大学轧制技术及连轧自动化国家重点实验室，沈阳 110819；
2. 燕山大学国家冷轧板带装备及工艺工程技术研究中心，秦皇岛 066004；
3. 东北大学材料电磁过程研究教育部重点实验室，沈阳 110819；
4. 广西先进铝加工创新中心有限责任公司，南宁 530007)
摘 要: 在铸造冷却速率分别为1.4 ℃/s与5.7 ℃/s的条件下制备了Al-Mg-Si-Mn铝合金铸锭，对铸锭进行了430 ℃、6h超低温均匀化，对均匀化后的合金样品进行了等轴热压试验。结果表明：水冷铜模样品中的共晶组织含量更少且尺寸更小。均匀化热处理后，大量α-Al(Fe, Mn)Si弥散相在铝基体中析出，水冷铜模样品的弥散相数量密度高于砂模样品。等轴热压过程中，水冷铜模样品具有更高的变形应力，原因是其α-Al(Fe, Mn)Si相数量密度更高，产生了更强的颗粒强化效应；砂模样品的边裂倾向更严重，原因是砂模样品中的粗大共晶组织更容易引起变形过程中的局部应力集中。
关键字: 铝合金；铸造冷却速率；α-Al(Fe, Mn)Si弥散相；热加工性能
（1. State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, China;
2. National Engineering Research Center for Equipment and Technology of Cold Strip Rolling, Yanshan University, Qinghuangdao 066004, China;
3. Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110819, China;
4. Guangxi Advanced Aluminum Processing Innovation Center Co., Ltd., Nanning 530007, China）
Abstract:Al-Mg-Si-Mn aluminum alloys were cast with different cooling rates of 1.4 ℃/s and 5.7 ℃/s, respectively. Ultra-low temperature homogenization at 430℃ for 6h was applied, followed by uniaxial hot compression tests to verify the hot workability. The results show that the water-cooled copper moldsample possesses a lower eutectics structure with a smaller size than the sand moldsample. After homogenization, a large amount of α-Al(Fe, Mn)Si dispersoids precipitate, and the number density of dispersoids in the water-cooled copper mold sample is greater than that in the sand mold sample. The water-cooled copper mold sample exhibits higher engineering stress levels during hot compression due to the enhanced dispersoids strengthening effect than that in sand mold sample. The edge cracks in water-cooled copper mold is less severe owing to the much finer initial eutectics generating depressed the risk of crack growth thanthat in the sand mold sample.
Key words: aluminum alloy; casting cooling rate;α-Al(Fe, Mn)Si dispersoid; hot workability
