微量Mn添加对Mg-6Zn-3Al镁合金非枝晶组织演变的影响
|
摘要
利用光镜(OM)、扫描电镜(SEM)、X射线衍射仪(XRD)研究了Mg-6Zn-3Al-xMn(x%=0%,0.1%,0.3%,0.5%,质量分数)合金的铸态组织和在等温热处理过程中的非枝晶组织演变规律。结果表明:铸态基体合金由α-Mg、Mg_2Zn_3、Mg_7Zn_3和Mg_(32)(Al,Zn)_(49))相组成。添加Mn后,析出了Al Mn和Al_8Mn_5相,且随Mn含量的增加,晶粒逐渐得到细化。合金经580℃等温保温30 min后,获得的非枝晶组织由初生α_1-Mg颗粒和包裹在共晶组织中二次水淬凝固形成的α_2-Mg颗粒及分布在初生颗粒间呈蜂窝状的共晶相组成。随着Mn含量增加,固相颗粒的平均尺寸和形状因子呈先减小后增加的趋势,组织中液相比例逐渐减少。当Mn含量(质量分数)为0.1%时,可获得近似球状、细小圆整、均匀分布的固相颗粒。在等温热处理过程中,溶质扩散和界面张力对组织演变起主导作用。Zn和Al溶质原子在液相中的成分起伏是初生颗粒在分离和球化过程中产生颈缩的重要原因。
The as-cast microstructure and non-dendritic microstructure evolution of Mg-6Zn-3Al alloys with varied Mn content(0%,0.1%,0.3%and 0.5%,in mass fraction)under isothermal heat treatment process were investigated with an OM,SEM and XRD,respectively.The results indicate that the as-cast Mn-free alloy is composed ofα-Mg,Mg_2Zn_3,Mg_7Zn_3 and Mg_(32)(Al,Zn)_(49) phases.When the minor Mn is added to the based alloy after,resulting in the creation of Al Mn and Al_8Mn_5 phases,meanwhile,the grains are gradually refined with the Mn content increasing.The alloys are isothermally treated at 580℃for 30 min,the obtained non-dendritic microstructures are comprised of primaryα_1-Mg particles andα_2-Mg particles existed in eutectic microstructures which form in secondary quenching solidification process as well as eutectic phases with alveolate morphologies distributed between the primary solid particles.With the increase of Mn content,the average size and shape factor of solid phase particles decrease first and then increase,the volume fraction of liquid phase decreases continuously.When the content of Mn is 0.1%,the similarly spherical,finer and roundness as well as uniform distribution solid phase particles are obtained.The solute diffusion and interfacial tension play a leading role in the microstructural evolution during isothermal heat treatment.The component fluctuation of Zn and Al solute atoms in liquid phase is an important reason for the generation of necking in the process of separation and spheroidization of primary particles.
The as-cast microstructure and non-dendritic microstructure evolution of Mg-6Zn-3Al alloys with varied Mn content(0%,0.1%,0.3%and 0.5%,in mass fraction)under isothermal heat treatment process were investigated with an OM,SEM and XRD,respectively.The results indicate that the as-cast Mn-free alloy is composed ofα-Mg,Mg_2Zn_3,Mg_7Zn_3 and Mg_(32)(Al,Zn)_(49) phases.When the minor Mn is added to the based alloy after,resulting in the creation of Al Mn and Al_8Mn_5 phases,meanwhile,the grains are gradually refined with the Mn content increasing.The alloys are isothermally treated at 580℃for 30 min,the obtained non-dendritic microstructures are comprised of primaryα_1-Mg particles andα_2-Mg particles existed in eutectic microstructures which form in secondary quenching solidification process as well as eutectic phases with alveolate morphologies distributed between the primary solid particles.With the increase of Mn content,the average size and shape factor of solid phase particles decrease first and then increase,the volume fraction of liquid phase decreases continuously.When the content of Mn is 0.1%,the similarly spherical,finer and roundness as well as uniform distribution solid phase particles are obtained.The solute diffusion and interfacial tension play a leading role in the microstructural evolution during isothermal heat treatment.The component fluctuation of Zn and Al solute atoms in liquid phase is an important reason for the generation of necking in the process of separation and spheroidization of primary particles.
引文
[1]张胜利,杨光昱,刘少军,介万奇.Mg-5.5Zn-2Gd-0.6Zr铸造镁合金的蠕变机制[J].中国有色金属学报,2012,22(2):331-336.ZHANG Sheng-li,YANG Guang-yu,LIU Shao-jun,JIE Wan-qi.Creep mechanism of Mg-5.5Zn-2Gd-0.6Zr cast alloy[J].The Chinese Journal of Nonferrous Metals,2012,22(2):331-336.
[2]严安庆,王霄,刘楚明,徐璐.Mg-4Y-2.5Nd-0.6Zr合金显微组织及力学性能的研究[J].兵器材料科学与工程,2013(5):17-20.YAN An-qing,WANG Xiao,LIU Chu-ming,XU Lu.Microstructure and mechanical properties of Mg-4Y-2.5Nd-0.6Zr alloy[J].Ordnance Material Science and Engineering,2013(5):17-20.
[3]甘俊雄,张帆,韩修柱,刘楚明.混合稀土对AZ80镁合金显微组织和力学性能的影响[J].兵器材料科学与工程,2015,38(1):81-84.GAN Jun-xiong,ZHANG Fan,HAN Xiu-zhu,LIU Chu-ming.Effects of mischmetal on microstructure and mechanical properties of AZ80 magnesium alloy[J].Ordnance Material Science and Engineering,2015,38(1):81-84.
[4]朱蓓蓓,孙扬善,万晓峰,薛烽.Mg-Zn-Al系变形镁合金的显微组织和力学性能[J].东南大学学报(自然科学版),2010,40(3):640-645.ZHU Bei-Bei,SUN Yang-shan,WAN Xiao-feng,XUE Feng.Microstructures and mechanical properties of Mg-Zn-Al wrought magnesium alloys[J].Journal of Southeast University(Natural Science Edition),2010,40(3):640-645.
[5]WANG B G,WANG X,ZHOU J X,ZHANG G F,LIU F.Effects of solution heat treatment on microstructure and mechanical properties of Mg-3Al-1Si-0.3Mn-x Sr alloy[J].Materials Science and Engineering A,2014,618:210-218.
[6]ZHANG Y,HUANG X F,MA Z D,LI Y,GUO F,YANG J C,MA Y,HAO Y.The influences of Al content on the microstructure and mechanical properties of as-cast Mg-6Zn magnesium alloys[J].Materials Science and Engineering A,2017,686:93-101.
[7]冯凯,黄晓锋,马颖,陈娟娟,郝远.固溶时间对ZA72镁合金显微组织及力学性能的影响[J].中国有色金属学报,2011,21(9):2035-2042.FENG Kai,HUANG Xiao-feng,MA Ying,CHEN Juan-juan,HAO Yuan.Effects of different solution time on microstructure and mechanical properties of ZA72 magnesium alloy[J].The Chinese Journal of Nonferrous Metals,2011,21(9):2035-2042.
[8]Fan Z.Semisolid metal processing[J].International Materials Reviews,2002,47(2):49-85.
[9]曹婧,乐启炽,张志强,宝磊,崔建忠.ZK60-2Ca镁合金半固态坯料的部分重熔[J].中国有色金属学报,2014,24(1):1-7.CAO Jing,LE Qi-chi,ZHANG Zhi-qiang,BAO Lei,CUI Jian-zhong.Partial remelting of semi-solid metal ingots of ZK60-2Ca magnesium alloy[J].The Chinese Journal of Nonferrous Metals,2014,24(1):1-7.
[10]刘伟,张英波,李彬,权高峰.半固态等温处理Mg-Zn-Y合金微观组织演变[J].稀有金属材料与工程,2015,44(12):3243-3247.LIU Wei,ZHANG Ying-bo,LI Bin,QUAN G F.Microstructure evolution of Mg-Zn-Y alloys during semi-solid isothermal heat treatment[J].Rare Metal Materials and Engineering,2015,44(12):3243-3247.
[11]胡勇,闫洪,陈国香.原位Mg2Si/AM60镁基复合材料半固态组织演变[J].材料工程,2009(6):56-59.HU Yong,YAN Hong,CHEN Guo-xiang.Semi-solid microstructure evolution of in situ synthesized Mg2 Si/AM60magnesium matrix composites[J].Journal of Materials Engineering,2009(6):56-59.
[12]孙兵,张英波,权高峰,李彬.AZ80镁合金半固态等温处理过程中的组织演变[J].稀有金属材料与工程,2016,45(2):404-408.SUN Bing,ZHANG Ying-bo,QUAN Gao-feng,LI Bin.Microstructures evolution of AZ80 magnesium alloy in semi-solid isothermal treatment process[J].Rare Metal Materials and Engineering,2016,45(2):404-408.
[13]ZHANG L,WU G H,WANG S H,DING W J.Effect of cooling condition on microstructure of semi-solid AZ91 slurry produced via ultrasonic vibration process[J].Transactions of Nonferrous Metals Society of China,2012,22(10):2357-2363.
[14]胡勇,倪旭武,胡强.二次加热对Al-0.3Ce合金半固态组织的影响[J].兵器材料科学与工程,2015,38(3):23-25.HU Yong,NI Xu-wu,HU Qiang.Effects of remelting process on semi-solid microstructure of Al-0.3Ce alloy[J].Ordnance Material Science and Engineering,2015,38(3):23-25.
[15]DU L,YAN H.Effect of isothermal heat-treated on the microstructure of ZA61 rare earth magnesium alloy[J].Chinese Journal of Materials Research,2012,26(2):169-174.
[16]ZHANG Y,HUANG X F,MA Y,CHEN T J,HAO Y.Effects of Sm addition on microstructural evolution of Mg-6Zn-0.4Zr alloy during semi-solid isothermal heat treatment[J].China Foundry,2017,14(2):433-440.
[17]SABRINA A K,YUKIO M,YOSHIHARU M,ZAINUDDIN B S.Influence of Mn content on mechanical properties and fatigue behavior of extruded Mg alloys[J].Materials Science and Engineering A,2006,420(1/2):315-321.
[18]STANFORD N,ATWELL D.The effect of Mn-rich precipitates on the strength of AZ31 extrudates[J].Metallurgical and Materials Transactions A,2013,44(10):4830-4843.
[19]王春建,金青林,周荣,蒋业华.Mn元素对高纯Mg-3Al合金晶粒尺寸的影响[J].中国有色金属学报,2010,20(8):1496-1500.WANG Chun-jian,JIN Qing-lin,ZHOU Rong,JIANG Ye-hua.Effect of Mn on grain size of high-purity Mg-3Al alloys[J].The Chinese Journal of Nonferrous Metals,2010,20(8):1496-1500.
[20]KHAN S A,MIYASHITA Y,MUTOH Y,SAJURI Z B.Influence of Mn content on mechanical properties and fatigue behavior of extruded Mg alloys[J].Materials Science and Engineering A,2006,420(1/2):315-321.
[21]冯凯,黄晓锋,马颖,阎峰云,郝远.ZA74镁合金非枝晶组织的演变过程及机理[J].中国有色金属学报,2013,23(3):635-644.FENG Kai,HUANG Xiao-feng,MA Ying,YAN Feng-yun,HAO Yuan.Non-dendritic microstructure evolution process and mechanism of ZA74 magnesium alloy[J].The Chinese Journal of Nonferrous Metals,2013,23(3):635-644.
[22]CHEN T J,JIANG X D,MA Y,LI Y D,HAO Y.Microstructural evolution and phase transformations during partial remelting of AZ91D magnesium alloy refined by Si C[J].Journal of Alloys and Compounds,2010,497(2):147-154.
[23]HAN L H,HU H,NORTHWOOD D O,LI N Y.Microstructure and nano-scale mechanical behavior of Mg-Al and Mg-Al-Ca alloys[J].Materials Science and Engineering A,2008,473:16-27.
[24]LASTER T,NUMBERG M R,JANZ A,HARTIG C,LETZIG D,SCHMID F R,BORMANN R.The influence of manganese on the microstructure and mechanical properties of AZ31 gravity cast alloys[J].Acta Mateialia,2006,54(11):3033-3041.
[25]胡勇,饶丽,胡强.等温热处理过程中半固态AZ91D镁合金组织演变[J].材料研究学报,2014,28(12):909-913.HU Yong,RAO Li,HU Qiang.Microstructure evolution of semi-solid AZ91D alloy during isothermal heat treatment process[J].Chinese Journal of Materials Research,2014,28(12):909-913.
[26]黄晓锋,张玉,秦牧岚,郝远.等温热处理对Mg-6Zn-3Cu合金半固态组织演变的影响[J].材料热处理学报,2016,37(8):53-59.HUANG Xiao-feng,ZHANG Yu,QIN Mu-lan,HAO Yuan.Effects of isothermal heat treatment on microstructural evolution of Mg-6Zn-3Cu alloy[J].Transactions of Materials and Heat Treatment,2016,37(8):53-59.
[27]高义民.金属凝固原理[M].西安:西安交通大学出版社,2010.GAO Yi-min.Metal Solidification Principle[M].Xi’an:Xi’an Jiaotong University Press,2010.
[28]张小立,李廷举,藤海涛,谢水生,金俊泽.等温热处理过程中铸态AZ91镁合金的微观组织演化[J].铸造,2007,56(10):1048-1052.ZHANG Xiao-li,LI Ting-ju,TENG Hai-tao,XIE Shui-sheng,JIN Jun-ze.Microstructure evolution of as-cast AZ91magnesium alloy during isothermal heat treatment[J].Foundry,2007,56(10):1048-1052.
[29]杜磊,闫洪.等温热处理对AZ61稀土镁合金半固态组织的影响[J].材料研究学报,2012,26(2):169-174.DU Lei,YAN Hong.Effect of isothermal heat-treated on the microstructure of ZA61 rare earth magnesium alloy[J].Chinese Journal of Materials Research,2012,26(2):169-174.
[30]乐启炽,张新建,崔建忠,路贵民,欧鹏.镁合金近液相线铸造半固态坯料的部分重熔[J].金属学报,2002,38(12):1266-1272.LE Qi-chi,ZHANG Xin-jian,CUI Jian-zhong,Lu Gui-min,OU Peng.Remelting of SSM ingot prepared by the near liquidus casting of AZ91D magnesium alloy[J].Acta Metallurgica Sinica,2002,38(12):1266-1272.
[31]李元东,郝远,陈体军,马颖.原始组织对半固态AZ91D镁合金重熔行为的影响[J].中国有色金属学报,2004,14(3):366-371.LI Yuan-dong,HAO Yuan,CHEN Ti-jun,MA Ying.Effects of different primary microstructure on semi-solid melting behavior of AZ91D magnesium alloy[J].The Chinese Journal of Nonferrous Metals,2004,14(3):366-371.
[2]严安庆,王霄,刘楚明,徐璐.Mg-4Y-2.5Nd-0.6Zr合金显微组织及力学性能的研究[J].兵器材料科学与工程,2013(5):17-20.YAN An-qing,WANG Xiao,LIU Chu-ming,XU Lu.Microstructure and mechanical properties of Mg-4Y-2.5Nd-0.6Zr alloy[J].Ordnance Material Science and Engineering,2013(5):17-20.
[3]甘俊雄,张帆,韩修柱,刘楚明.混合稀土对AZ80镁合金显微组织和力学性能的影响[J].兵器材料科学与工程,2015,38(1):81-84.GAN Jun-xiong,ZHANG Fan,HAN Xiu-zhu,LIU Chu-ming.Effects of mischmetal on microstructure and mechanical properties of AZ80 magnesium alloy[J].Ordnance Material Science and Engineering,2015,38(1):81-84.
[4]朱蓓蓓,孙扬善,万晓峰,薛烽.Mg-Zn-Al系变形镁合金的显微组织和力学性能[J].东南大学学报(自然科学版),2010,40(3):640-645.ZHU Bei-Bei,SUN Yang-shan,WAN Xiao-feng,XUE Feng.Microstructures and mechanical properties of Mg-Zn-Al wrought magnesium alloys[J].Journal of Southeast University(Natural Science Edition),2010,40(3):640-645.
[5]WANG B G,WANG X,ZHOU J X,ZHANG G F,LIU F.Effects of solution heat treatment on microstructure and mechanical properties of Mg-3Al-1Si-0.3Mn-x Sr alloy[J].Materials Science and Engineering A,2014,618:210-218.
[6]ZHANG Y,HUANG X F,MA Z D,LI Y,GUO F,YANG J C,MA Y,HAO Y.The influences of Al content on the microstructure and mechanical properties of as-cast Mg-6Zn magnesium alloys[J].Materials Science and Engineering A,2017,686:93-101.
[7]冯凯,黄晓锋,马颖,陈娟娟,郝远.固溶时间对ZA72镁合金显微组织及力学性能的影响[J].中国有色金属学报,2011,21(9):2035-2042.FENG Kai,HUANG Xiao-feng,MA Ying,CHEN Juan-juan,HAO Yuan.Effects of different solution time on microstructure and mechanical properties of ZA72 magnesium alloy[J].The Chinese Journal of Nonferrous Metals,2011,21(9):2035-2042.
[8]Fan Z.Semisolid metal processing[J].International Materials Reviews,2002,47(2):49-85.
[9]曹婧,乐启炽,张志强,宝磊,崔建忠.ZK60-2Ca镁合金半固态坯料的部分重熔[J].中国有色金属学报,2014,24(1):1-7.CAO Jing,LE Qi-chi,ZHANG Zhi-qiang,BAO Lei,CUI Jian-zhong.Partial remelting of semi-solid metal ingots of ZK60-2Ca magnesium alloy[J].The Chinese Journal of Nonferrous Metals,2014,24(1):1-7.
[10]刘伟,张英波,李彬,权高峰.半固态等温处理Mg-Zn-Y合金微观组织演变[J].稀有金属材料与工程,2015,44(12):3243-3247.LIU Wei,ZHANG Ying-bo,LI Bin,QUAN G F.Microstructure evolution of Mg-Zn-Y alloys during semi-solid isothermal heat treatment[J].Rare Metal Materials and Engineering,2015,44(12):3243-3247.
[11]胡勇,闫洪,陈国香.原位Mg2Si/AM60镁基复合材料半固态组织演变[J].材料工程,2009(6):56-59.HU Yong,YAN Hong,CHEN Guo-xiang.Semi-solid microstructure evolution of in situ synthesized Mg2 Si/AM60magnesium matrix composites[J].Journal of Materials Engineering,2009(6):56-59.
[12]孙兵,张英波,权高峰,李彬.AZ80镁合金半固态等温处理过程中的组织演变[J].稀有金属材料与工程,2016,45(2):404-408.SUN Bing,ZHANG Ying-bo,QUAN Gao-feng,LI Bin.Microstructures evolution of AZ80 magnesium alloy in semi-solid isothermal treatment process[J].Rare Metal Materials and Engineering,2016,45(2):404-408.
[13]ZHANG L,WU G H,WANG S H,DING W J.Effect of cooling condition on microstructure of semi-solid AZ91 slurry produced via ultrasonic vibration process[J].Transactions of Nonferrous Metals Society of China,2012,22(10):2357-2363.
[14]胡勇,倪旭武,胡强.二次加热对Al-0.3Ce合金半固态组织的影响[J].兵器材料科学与工程,2015,38(3):23-25.HU Yong,NI Xu-wu,HU Qiang.Effects of remelting process on semi-solid microstructure of Al-0.3Ce alloy[J].Ordnance Material Science and Engineering,2015,38(3):23-25.
[15]DU L,YAN H.Effect of isothermal heat-treated on the microstructure of ZA61 rare earth magnesium alloy[J].Chinese Journal of Materials Research,2012,26(2):169-174.
[16]ZHANG Y,HUANG X F,MA Y,CHEN T J,HAO Y.Effects of Sm addition on microstructural evolution of Mg-6Zn-0.4Zr alloy during semi-solid isothermal heat treatment[J].China Foundry,2017,14(2):433-440.
[17]SABRINA A K,YUKIO M,YOSHIHARU M,ZAINUDDIN B S.Influence of Mn content on mechanical properties and fatigue behavior of extruded Mg alloys[J].Materials Science and Engineering A,2006,420(1/2):315-321.
[18]STANFORD N,ATWELL D.The effect of Mn-rich precipitates on the strength of AZ31 extrudates[J].Metallurgical and Materials Transactions A,2013,44(10):4830-4843.
[19]王春建,金青林,周荣,蒋业华.Mn元素对高纯Mg-3Al合金晶粒尺寸的影响[J].中国有色金属学报,2010,20(8):1496-1500.WANG Chun-jian,JIN Qing-lin,ZHOU Rong,JIANG Ye-hua.Effect of Mn on grain size of high-purity Mg-3Al alloys[J].The Chinese Journal of Nonferrous Metals,2010,20(8):1496-1500.
[20]KHAN S A,MIYASHITA Y,MUTOH Y,SAJURI Z B.Influence of Mn content on mechanical properties and fatigue behavior of extruded Mg alloys[J].Materials Science and Engineering A,2006,420(1/2):315-321.
[21]冯凯,黄晓锋,马颖,阎峰云,郝远.ZA74镁合金非枝晶组织的演变过程及机理[J].中国有色金属学报,2013,23(3):635-644.FENG Kai,HUANG Xiao-feng,MA Ying,YAN Feng-yun,HAO Yuan.Non-dendritic microstructure evolution process and mechanism of ZA74 magnesium alloy[J].The Chinese Journal of Nonferrous Metals,2013,23(3):635-644.
[22]CHEN T J,JIANG X D,MA Y,LI Y D,HAO Y.Microstructural evolution and phase transformations during partial remelting of AZ91D magnesium alloy refined by Si C[J].Journal of Alloys and Compounds,2010,497(2):147-154.
[23]HAN L H,HU H,NORTHWOOD D O,LI N Y.Microstructure and nano-scale mechanical behavior of Mg-Al and Mg-Al-Ca alloys[J].Materials Science and Engineering A,2008,473:16-27.
[24]LASTER T,NUMBERG M R,JANZ A,HARTIG C,LETZIG D,SCHMID F R,BORMANN R.The influence of manganese on the microstructure and mechanical properties of AZ31 gravity cast alloys[J].Acta Mateialia,2006,54(11):3033-3041.
[25]胡勇,饶丽,胡强.等温热处理过程中半固态AZ91D镁合金组织演变[J].材料研究学报,2014,28(12):909-913.HU Yong,RAO Li,HU Qiang.Microstructure evolution of semi-solid AZ91D alloy during isothermal heat treatment process[J].Chinese Journal of Materials Research,2014,28(12):909-913.
[26]黄晓锋,张玉,秦牧岚,郝远.等温热处理对Mg-6Zn-3Cu合金半固态组织演变的影响[J].材料热处理学报,2016,37(8):53-59.HUANG Xiao-feng,ZHANG Yu,QIN Mu-lan,HAO Yuan.Effects of isothermal heat treatment on microstructural evolution of Mg-6Zn-3Cu alloy[J].Transactions of Materials and Heat Treatment,2016,37(8):53-59.
[27]高义民.金属凝固原理[M].西安:西安交通大学出版社,2010.GAO Yi-min.Metal Solidification Principle[M].Xi’an:Xi’an Jiaotong University Press,2010.
[28]张小立,李廷举,藤海涛,谢水生,金俊泽.等温热处理过程中铸态AZ91镁合金的微观组织演化[J].铸造,2007,56(10):1048-1052.ZHANG Xiao-li,LI Ting-ju,TENG Hai-tao,XIE Shui-sheng,JIN Jun-ze.Microstructure evolution of as-cast AZ91magnesium alloy during isothermal heat treatment[J].Foundry,2007,56(10):1048-1052.
[29]杜磊,闫洪.等温热处理对AZ61稀土镁合金半固态组织的影响[J].材料研究学报,2012,26(2):169-174.DU Lei,YAN Hong.Effect of isothermal heat-treated on the microstructure of ZA61 rare earth magnesium alloy[J].Chinese Journal of Materials Research,2012,26(2):169-174.
[30]乐启炽,张新建,崔建忠,路贵民,欧鹏.镁合金近液相线铸造半固态坯料的部分重熔[J].金属学报,2002,38(12):1266-1272.LE Qi-chi,ZHANG Xin-jian,CUI Jian-zhong,Lu Gui-min,OU Peng.Remelting of SSM ingot prepared by the near liquidus casting of AZ91D magnesium alloy[J].Acta Metallurgica Sinica,2002,38(12):1266-1272.
[31]李元东,郝远,陈体军,马颖.原始组织对半固态AZ91D镁合金重熔行为的影响[J].中国有色金属学报,2004,14(3):366-371.LI Yuan-dong,HAO Yuan,CHEN Ti-jun,MA Ying.Effects of different primary microstructure on semi-solid melting behavior of AZ91D magnesium alloy[J].The Chinese Journal of Nonferrous Metals,2004,14(3):366-371.