初晶硅形貌與室溫拉伸性能的影響
(1．東北大學(xué) 材料各向異性與織構(gòu)工程教育部重點(diǎn)實(shí)驗(yàn)室，沈陽 110004；
2．東北大學(xué) 材料電磁過程研究教育部重點(diǎn)實(shí)驗(yàn)室，沈陽 110004)
摘 要: 研究了磷變質(zhì)對半連續(xù)鑄造Al-17.5Si-4.5Cu-1Zn-0.7Mg-0.5Ni變形合金初晶硅形貌與室溫拉伸性能的影響。結(jié)果表明：磷變質(zhì)處理后，鑄錠(直徑100 mm)中初晶硅形核率增加、顆粒分布均勻，其心部初晶硅平均尺寸由未變質(zhì)處理的37 μm細(xì)化到19 μm；鑄態(tài)變質(zhì)處理合金室溫抗拉強(qiáng)度為265 MPa，T6狀態(tài)抗拉強(qiáng)度為345 MPa；實(shí)現(xiàn)了大壓下量熱變形，熱變形變質(zhì)處理合金在T6狀態(tài)下，抗拉強(qiáng)度達(dá)到383 MPa，伸長率為1.15%。
關(guān)鍵字: Al-Si合金；初晶硅；磷變質(zhì)；熱變形；拉伸性能
primary silicon particles and mechanical properties of
wrought Al-17.5Si-4.5Cu-1Zn-0.7Mg-0.5Ni alloy
（1. Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education,
Northeastern University, Shenyang 110004, China;
2. Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education,
Northeastern University, Shenyang 110004, China）
Abstract:The effects of phosphorus modification on the morphology of primary silicon particles and mechanical properties of a wrought direct chill (DC) cast Al-17.5Si-4.5Cu-1Zn-0.7Mg-0.5Ni alloy were investigated. The results show that the addition of phosphorus increases the nucleation rate of primary Si in the billet (100 mm in diameter) leading to fine and uniform distribution of primary Si particles. The average size of the primary Si particles in the modified alloy in the central region of the billet is 19μm, comparing with that of 37μm in the unmodified alloy. The achieved ultimate tensile strength (UTS) of the modified alloy is 265 MPa in the as-cast state and 345 MPa in T6 condition. Hot deformation of modified and unmodified alloys with high per-pass reduction is carried out. The UTS and elongation of the hot-deformed modified alloy in T6 condition are 383MPa and 1.15%, respectively.
Key words: Al-Si alloy; primary silicon; phosphorus modification; hot deformation; tensile property
