不同电磁场作用下Al-Sn合金的凝固组织
|
摘要
Al-Sn合金由于具有大熔点差和宽结晶温度区间,易出现合金化不充分和晶粒充分生长形成粗大枝晶组织,造成比较严重的偏析。在凝固过程中施加不同电磁场和改变电流大小以获得组织均匀的Al-Sn合金。结果表明,施加电磁场后,Al-Sn合金晶粒明显细化,且行波磁场与复合磁场细化效果更加明显。Al-Sn合金中第二相偏析现象减轻,且随着电流强度增加,第二相分布更加均匀;通过对行波磁场(RMF)、旋转磁场(TMF)、复合磁场(RMF+TMF)处理后Al-Sn合金中的第二相分布比较,发现施加旋转磁场时,部分富Sn相有偏聚现象;而在行波磁场与复合磁场作用下,富Sn相没有明显的偏聚。
Due to the large difference of melting point and wide range of crystallization temperature,the alloying of Al-Sn alloy was prone to be insufficient and the coarse dendritic structure with serious segregation was also formed easily,and different type and current intensity of electromagnetic field was applied to obtain Al-Sn alloy with uniform microstructure.The results show that electromagnetic field has a great effect on the grain refinement,and with the enhancement of electromagnetic intensity,the grain will be finer.The segregation of second phase in Al-Sn alloy is weakened,and with the increase of the current intensity,the distribution of second phase becomes more uniform.By comparing the second phase of RMF、TMF、RMF+TMF treated Al-Sn alloy,it can be concluded that the tin-rich phase is segregated with RMF,and there is absence of segregation of tin-rich phase with the TMF and TMF+RMF treatment.
Due to the large difference of melting point and wide range of crystallization temperature,the alloying of Al-Sn alloy was prone to be insufficient and the coarse dendritic structure with serious segregation was also formed easily,and different type and current intensity of electromagnetic field was applied to obtain Al-Sn alloy with uniform microstructure.The results show that electromagnetic field has a great effect on the grain refinement,and with the enhancement of electromagnetic intensity,the grain will be finer.The segregation of second phase in Al-Sn alloy is weakened,and with the increase of the current intensity,the distribution of second phase becomes more uniform.By comparing the second phase of RMF、TMF、RMF+TMF treated Al-Sn alloy,it can be concluded that the tin-rich phase is segregated with RMF,and there is absence of segregation of tin-rich phase with the TMF and TMF+RMF treatment.
引文
[1]CAHN R W.Binary alloy phase diagrams[J].Advanced Materials,1991,3(12):628-629.
[2]JOYCE M R,SYNGELLAKIS S,REED P A S.Fatigue crack initiation and early growth in a multiphase Al alloy included in a multilayer material system[J].Metal Science Journal,2004,20(1):47-56.
[3]邓秋洁.机械合金化Al-12Sn-xMgH2轴承合金组织结构及性能研究[D].广州:华南理工大学,2015.
[4]YUAN G C,LI Z J,LOU Y X,et al.Study on crystallization and microstructure for new series of Al-Sn-Si alloys[J].Materials Science&Engineering,2000,A280(1):108-115.
[5]LIU X,ZENG M Q,MA Y,et al.Wear behavior of Al-Sn alloys with different distribution of Sn dispersoids manipulated by mechanical alloying and sintering[J].Wear,2008,265(11):1 857-1 863.
[6]USUI M,IWAI K,ASAI S.Crystal alignment of Sn-Pb alloy by controlled imposition of a static magnetic field and an alternating electric current during solidification[J].ISIJ International,2006,46(6):859-863.
[7]WANG B,YANG Y S,SUN M L.Microstructure refinement of AZ31alloy solidified with pulsed magnetic field[J].Transactions of Nonferrous Metals Society of China,2010,18(9):536-540.
[8]万刚,武保林,赵玉华,等.脉冲电流对Zn-42%Al合金定向凝固行为的影响[J].铸造技术,2005,26(12):1 124-1 126.
[9]ZUO Y B,CUI J Z,MOU D,et al.Effect of electromagnetic field on microstructure and macrosegregation of flat ingot of 2524aluminium alloy[J].Transactions of Nonferrous Metals Society of China,2014,24(7):2 408-2 413.
[10]许雄.电磁场对镍基高温合金K403定向凝固组织的影响研究[D].西安:西北工业大学,2005.
[11]FLEMINGS M C.Behavior of metal alloys in the semisolid state[J].Metallurgical Transactions,1991,B22(6):269-293.
[12]HELAWELL A.Grain Evolution in Conventional and Rheocasting[C].Proceeding of the 4th S2P,UK,1996.
[13]PILLING J,HELAWELL A.Mechanical deformation of dendrites by fluid flow[J].Metallurgical and Materials Transactions,1996,A27(1):229-232.
[14]张景新,张奎,刘国钧,等.电磁剪切制备半固态材料非枝晶组织的形成机制[J].中国有色金属学报,2000,10(4):511-514.
[15]FAN Z.Twin-screw Rheoforming Technologies for Semisolid Processing of Mg-alloys[C].Tsukuba,Japan,2002.
[16]邱乐园.电磁作用下熔体非金属颗粒运动行为的数值模拟研究[D].北京:清华大学,2013.
[2]JOYCE M R,SYNGELLAKIS S,REED P A S.Fatigue crack initiation and early growth in a multiphase Al alloy included in a multilayer material system[J].Metal Science Journal,2004,20(1):47-56.
[3]邓秋洁.机械合金化Al-12Sn-xMgH2轴承合金组织结构及性能研究[D].广州:华南理工大学,2015.
[4]YUAN G C,LI Z J,LOU Y X,et al.Study on crystallization and microstructure for new series of Al-Sn-Si alloys[J].Materials Science&Engineering,2000,A280(1):108-115.
[5]LIU X,ZENG M Q,MA Y,et al.Wear behavior of Al-Sn alloys with different distribution of Sn dispersoids manipulated by mechanical alloying and sintering[J].Wear,2008,265(11):1 857-1 863.
[6]USUI M,IWAI K,ASAI S.Crystal alignment of Sn-Pb alloy by controlled imposition of a static magnetic field and an alternating electric current during solidification[J].ISIJ International,2006,46(6):859-863.
[7]WANG B,YANG Y S,SUN M L.Microstructure refinement of AZ31alloy solidified with pulsed magnetic field[J].Transactions of Nonferrous Metals Society of China,2010,18(9):536-540.
[8]万刚,武保林,赵玉华,等.脉冲电流对Zn-42%Al合金定向凝固行为的影响[J].铸造技术,2005,26(12):1 124-1 126.
[9]ZUO Y B,CUI J Z,MOU D,et al.Effect of electromagnetic field on microstructure and macrosegregation of flat ingot of 2524aluminium alloy[J].Transactions of Nonferrous Metals Society of China,2014,24(7):2 408-2 413.
[10]许雄.电磁场对镍基高温合金K403定向凝固组织的影响研究[D].西安:西北工业大学,2005.
[11]FLEMINGS M C.Behavior of metal alloys in the semisolid state[J].Metallurgical Transactions,1991,B22(6):269-293.
[12]HELAWELL A.Grain Evolution in Conventional and Rheocasting[C].Proceeding of the 4th S2P,UK,1996.
[13]PILLING J,HELAWELL A.Mechanical deformation of dendrites by fluid flow[J].Metallurgical and Materials Transactions,1996,A27(1):229-232.
[14]张景新,张奎,刘国钧,等.电磁剪切制备半固态材料非枝晶组织的形成机制[J].中国有色金属学报,2000,10(4):511-514.
[15]FAN Z.Twin-screw Rheoforming Technologies for Semisolid Processing of Mg-alloys[C].Tsukuba,Japan,2002.
[16]邱乐园.电磁作用下熔体非金属颗粒运动行为的数值模拟研究[D].北京:清华大学,2013.