Sc对Al-Si-Mg-Cu-Ti合金铸态组织和力学性能的影响
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摘要
借助金相显微镜、扫描电镜、透射电镜、布氏硬度计和万能试验机,试验研究了Sc对Al-3.0Si-0.45Mg-0.45Cu-0.15Ti合金铸态组织和力学性能的影响。结果表明,在试验合金中添加稀土元素Sc,使合金在凝固过程中析出Al3(Sc,Ti)初生相,初生相与α(Al)基体共格,符合点阵匹配原理,成为有效的非均质晶核,可显著细化合金的铸态组织。随着Sc含量(w(Sc)0~0.56%)的增加,合金的铸态组织由粗大的树枝晶变为细小的等轴晶,合金的硬度、抗拉强度和伸长率也随着Sc含量的增加而升高。时效过程中析出的Al3(Sc,Ti)沉淀相密度高,细小弥散,具有钉扎位错,稳定亚结构,阻碍亚晶长大及晶界迁移的作用。
The influences of Sc addition on the casting structures and mechanical properties of Al-3. 0 Si-0. 45 Mg-0. 45 Cu-0. 15 Ti alloys were investigated by metallographic microscope,scanning electron microscopy with energy dispersive X-ray( SEM-EDX),transmission electron microscopy( TEM),Brinell tester and universal testing machine. The result shows that the primary Al_3( Sc,Ti) particles precipitated from the melt during solidification produce a substantial refinement of grain size of as-cast microstructures of the alloys,which have the same crystal structure of α( Al),and comply with the lattice matching principle. With increase content of Sc( 0 ~ 0. 56%),the growth morphology of as-cast microstructures change from denfritic to fine equiaxed grain. The hardness,tensile strength and elongation are also enhanced with the increase content of Sc. The dispersed secondary Al_3( Sc,Ti) precipitated during aging treatment can strongly pin dislocations,stabilize substructures and inhibit subgrain growth and the movement of boundaries.
The influences of Sc addition on the casting structures and mechanical properties of Al-3. 0 Si-0. 45 Mg-0. 45 Cu-0. 15 Ti alloys were investigated by metallographic microscope,scanning electron microscopy with energy dispersive X-ray( SEM-EDX),transmission electron microscopy( TEM),Brinell tester and universal testing machine. The result shows that the primary Al_3( Sc,Ti) particles precipitated from the melt during solidification produce a substantial refinement of grain size of as-cast microstructures of the alloys,which have the same crystal structure of α( Al),and comply with the lattice matching principle. With increase content of Sc( 0 ~ 0. 56%),the growth morphology of as-cast microstructures change from denfritic to fine equiaxed grain. The hardness,tensile strength and elongation are also enhanced with the increase content of Sc. The dispersed secondary Al_3( Sc,Ti) precipitated during aging treatment can strongly pin dislocations,stabilize substructures and inhibit subgrain growth and the movement of boundaries.
引文
[1]Zhang Wenda,Liu Yun,Yang Jing,Dang Jinzhi,Xu Hong,Du henmin.Effects of Sc content on the microstructure of As-Cast Al-7 wt.%Si alloys[J].Materials Characterization,2012,66:104-110.
[2]Meng Yi,Zhao Zhihao,Cui Jianzhong.Effect of minor Zr and Sc on microstructures and mechanical properties of Al-Mg-Si-Cu-Cr-V alloys[J].Transactions of Nonferrous Metals Society of China,2013,23(7):1882-1889.
[3]ROYSET J,RYUM N.Scandium in aluminium alloys[J].International Materials Reviews,2005,50(1):19-44.
[4]NORMAN A F,HYDE K,COSTELLO F,THOMPSON S,BIRLEY S,PRANGNELL P B.Examination of the effect of Sc on 2000 and7000 series aluminum alloy castings:For improvements in fusion welding[J].Materials Science&Engineering A,2003,354:188-198.
[5]MILMAN Y V,SIRKO A I,LOTSKO D V,SENKOV O N,MIRACLE D B.Microstructure and mechanical properties of cast and wrought Al-Zn-Mg-Cu alloys modified with Zr and Sc[J].Mater Science Forum,2002,396/402:1127-1132.
[6]戴晓元,夏长清,马科,等.Sc对Al-Zn-Mg-Cu-Zr合金铸态组织和力学性能的影响[J].中国有色金属学报,2007,17(8):1324-1329.
[7]Yu Kun,Li Wenxian,Li Songrui,Zhao Jun.Mechanical properties and microstructure of aluminum alloy 2618 with Al3(Sc,Zr)phases[J].Materials Science&Engineering A,2004,368:88-93.
[8]Yin Zhimin,Jiang Feng,Pan Qinglin,et al.Microstructures and mechanical properties of Al-Mg and Al-Zn-Mg based alloys containing minor scandium and zirconium[J].Transactions of Nonferrous Metals Society of China,2003,13(3):515-520.
[9]Zeng Fanhao,Xia Changqing,Gu Yi.The isothermal section of the Al-4Mg-Sc-Zr quaternary system in Al-rich range[J].Journal of Alloys and Compounds,2004,363:175-181.
[10]LI G,ZHAO N,LIU T,et al.Effect of Sc/Zr ratio on the microstructure and mechanical properties of new type of Al—Zn—Mg—Sc—Zr alloys[J].Materials Science&Engineering A,2014,617:219—227.
[11]NORMAN A F,PRANGNELL P B,MCEWEN R S.The solidification behavior of dilute aluminium-scandium alloys[J].Acta Materialia,1998,46(16):5715-5732.
[12]MIURA Y,SHIOYAMA T,HARE D.Recrystallization of Al-3Mg and Al-3Mg-0.2Sc alloys[J].Mater Science Forum,1996,217/222:505-510.
[2]Meng Yi,Zhao Zhihao,Cui Jianzhong.Effect of minor Zr and Sc on microstructures and mechanical properties of Al-Mg-Si-Cu-Cr-V alloys[J].Transactions of Nonferrous Metals Society of China,2013,23(7):1882-1889.
[3]ROYSET J,RYUM N.Scandium in aluminium alloys[J].International Materials Reviews,2005,50(1):19-44.
[4]NORMAN A F,HYDE K,COSTELLO F,THOMPSON S,BIRLEY S,PRANGNELL P B.Examination of the effect of Sc on 2000 and7000 series aluminum alloy castings:For improvements in fusion welding[J].Materials Science&Engineering A,2003,354:188-198.
[5]MILMAN Y V,SIRKO A I,LOTSKO D V,SENKOV O N,MIRACLE D B.Microstructure and mechanical properties of cast and wrought Al-Zn-Mg-Cu alloys modified with Zr and Sc[J].Mater Science Forum,2002,396/402:1127-1132.
[6]戴晓元,夏长清,马科,等.Sc对Al-Zn-Mg-Cu-Zr合金铸态组织和力学性能的影响[J].中国有色金属学报,2007,17(8):1324-1329.
[7]Yu Kun,Li Wenxian,Li Songrui,Zhao Jun.Mechanical properties and microstructure of aluminum alloy 2618 with Al3(Sc,Zr)phases[J].Materials Science&Engineering A,2004,368:88-93.
[8]Yin Zhimin,Jiang Feng,Pan Qinglin,et al.Microstructures and mechanical properties of Al-Mg and Al-Zn-Mg based alloys containing minor scandium and zirconium[J].Transactions of Nonferrous Metals Society of China,2003,13(3):515-520.
[9]Zeng Fanhao,Xia Changqing,Gu Yi.The isothermal section of the Al-4Mg-Sc-Zr quaternary system in Al-rich range[J].Journal of Alloys and Compounds,2004,363:175-181.
[10]LI G,ZHAO N,LIU T,et al.Effect of Sc/Zr ratio on the microstructure and mechanical properties of new type of Al—Zn—Mg—Sc—Zr alloys[J].Materials Science&Engineering A,2014,617:219—227.
[11]NORMAN A F,PRANGNELL P B,MCEWEN R S.The solidification behavior of dilute aluminium-scandium alloys[J].Acta Materialia,1998,46(16):5715-5732.
[12]MIURA Y,SHIOYAMA T,HARE D.Recrystallization of Al-3Mg and Al-3Mg-0.2Sc alloys[J].Mater Science Forum,1996,217/222:505-510.