(北京科技大學 材料科學與工程學院，北京 100083)
摘 要: 將自主研發(fā)的強制對流攪拌制漿裝置(FCM)與壓鑄機結合，以汽車控制臂為例，成功實現A380鋁合金的流變壓鑄成形。研究FCM工藝參數下鑄件組織特征的演變，對比傳統壓鑄與FCM流變壓鑄工藝下鑄件顯微組織、內部缺陷和力學性能的差異，分析FCM流變壓鑄工藝組織形成機理及其凝固行為。結果表明：適當提高螺桿轉速或降低內筒溫度，均有利于改善鑄件的組織形態(tài)；FCM流變壓鑄工藝不僅可以獲得內部組織細小、圓整且分布均勻的鑄件，而且可以顯著減少鑄件內部氣孔缺陷和提高鑄件的力學性能。和傳統壓鑄件相比，FCM流變壓鑄件的抗拉強度、屈服強度和伸長率分別提高了10%、4%和140%。
關鍵字: A380鋁合金；強制對流攪拌；流變壓鑄；組織演變；力學性能
（School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract: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 α(Al) 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.
Key words: A380 aluminum alloy; forced convection mixing; rheo-diecasting; microstructure evolution; mechanical property
