流变压铸A380铝合金的显微组织与力学性能  

Microstructures and mechanical properties of A380 aluminum alloy produced by rheo-diecasting process

作　　者：祁明凡 康永林[1] 周冰[1] 张欢欢[1] 朱国明[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《中国有色金属学报》2015年第8期2029-2039,共11页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展计划资助项目(2011CB606302);国家高技术研究发展计划资助项目(2013AA031001)

摘　　要：将自主研发的强制对流搅拌制浆装置(FCM)与压铸机结合,以汽车控制臂为例,成功实现A380铝合金的流变压铸成形。研究FCM工艺参数下铸件组织特征的演变,对比传统压铸与FCM流变压铸工艺下铸件显微组织、内部缺陷和力学性能的差异,分析FCM流变压铸工艺组织形成机理及其凝固行为。结果表明:适当提高螺杆转速或降低内筒温度,均有利于改善铸件的组织形态;FCM流变压铸工艺不仅可以获得内部组织细小、圆整且分布均匀的铸件,而且可以显著减少铸件内部气孔缺陷和提高铸件的力学性能。和传统压铸件相比,FCM流变压铸件的抗拉强度、屈服强度和伸长率分别提高了10%、4%和140%。Taking auto control arms for example, the rheo-diecasting process of A380 alloy was obtained by combing a self-developed forced convection mixing rheoforming machine （FCM） with a diecasting machine. The microstructural characteristics of FCM rheo-diecasting parts in various processing parameters were investigated. The differences of microstructures, internal defects and mechanical properties in traditional diecasting parts and rheo-diecasting parts were compared. The formation mechanism and solidification behavior of semisolid slurry were analyzed in FCM rheo-diecasting process. The results show that raising rotation speed or decreasing barrel temperature appropriately is beneficial to optimize the microstructure of rheo-diecasting parts. The process not only can get parts with fine, spherical and uniformly distributed primary a（A1） particles, but also is able to increase mechanical properties and decrease pore defects of parts evidently. Compared with traditional diecasting, the tensile strength, yield strength and elongation of FCM rheo-diecasting parts are increased by 10%, 4% and 140%, respectively.

关 键 词：A380铝合金 强制对流搅拌 流变压铸 组织演变 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]