Ce对Mg-3Al-2.5Si合金中初生Mg_2Si相的变质作用与机理
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摘要
采用金相光学显微镜(OM)、扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射(XRD)等手段,研究了不同Ce含量对Mg-3Al-2. 5Si合金中初生Mg_2Si相的变质效果。结果表明,加入适量Ce可以有效细化初生Mg_2Si相,初生Mg_2Si逐步由"骨骼枝"状和"花瓣"状向细小规则的多边形状转变。Ce的加入量为0. 2%和0. 6%时,对初生Mg_2Si相的变质机理主要以"吸附毒化"机制为主。当Ce加入量为1%时,对初生Mg_2Si相的变质和细化效果最好,尺寸减小到18μm以下。合金基体中形成了大量细小短杆状CeSi_2相,可成为初生Mg_2Si的有效形核核心,此时Ce对初生Mg_2Si的变质有"吸附毒化"和异质形核机制两方面作用;当Ce加入量超过1. 6%时,初生Mg_2Si再次粗化,表现出过变质效果。
Metallographic optical microscope( OM),scanning electron microscope( SEM),energy dispersive spectrum analysis( EDS) and X-ray diffraction( XRD) were used to study the metamorphism effect of the primary Mg_2 Si phase in Mg-3 Al-2.5 Si alloy with different Ce content.Results show that the addition of appropriate amount of Ce element can effectively refine the primary Mg_2 Si phase,and the primary Mg_2 Si gradually changes from the "skeletal branch" shape and the " petal" shape to the fine regular polygonal shape.When the addition amount of Ce is0.2% and 0.6%,the mechanism of metamorphism of the primary Mg_2 Si phase is mainly based on the mechanism of " adsorption poisoning".The optimal metamorphism and refinement effect on the primary Mg_2 Si phase is obtained with addition of about 1% Ce,and the size of the primary Mg_2 Si is reduced to 18 μm or less.A large number of short rod-like Ce Si_2 phases are formed in the alloy matrix,which can be the effective nucleation core of primary Mg_2 Si.At this time,Ce has the effects of"adsorption poisoning"and heterogeneous nucleation mechanism on the metamorphism of primary Mg_2 Si; However,when the addition of Ce exceeds 1.6%,the primary Mg_2 Si is coarsened again and exhibits an over-metamorphism effect.
Metallographic optical microscope( OM),scanning electron microscope( SEM),energy dispersive spectrum analysis( EDS) and X-ray diffraction( XRD) were used to study the metamorphism effect of the primary Mg_2 Si phase in Mg-3 Al-2.5 Si alloy with different Ce content.Results show that the addition of appropriate amount of Ce element can effectively refine the primary Mg_2 Si phase,and the primary Mg_2 Si gradually changes from the "skeletal branch" shape and the " petal" shape to the fine regular polygonal shape.When the addition amount of Ce is0.2% and 0.6%,the mechanism of metamorphism of the primary Mg_2 Si phase is mainly based on the mechanism of " adsorption poisoning".The optimal metamorphism and refinement effect on the primary Mg_2 Si phase is obtained with addition of about 1% Ce,and the size of the primary Mg_2 Si is reduced to 18 μm or less.A large number of short rod-like Ce Si_2 phases are formed in the alloy matrix,which can be the effective nucleation core of primary Mg_2 Si.At this time,Ce has the effects of"adsorption poisoning"and heterogeneous nucleation mechanism on the metamorphism of primary Mg_2 Si; However,when the addition of Ce exceeds 1.6%,the primary Mg_2 Si is coarsened again and exhibits an over-metamorphism effect.
引文
[1]闫蕴琪,张廷杰,邓炬,等.耐热镁合金的研究现状与发展方向[J].稀有金属材料与工程,2004,33(6):561-565.YAN Yunqi,ZHANG Tingjie,DENG Ju,et al. Research and development of heat resistant Mg alloys[J]. Rare Metal Materials and Engineering,2004,33(6):561-565.
[2]杨明波,潘复生,白亮,等.合金元素对Mg-Al-Si系镁合金中Mg2Si相形貌影响的研究进展[J].热加工工艺,2007,36(14):71-74.YANG Mingbo, PAN Fusheng, BAI Liang, et al.Development of effects of alloy elements on morpohoty of Mg2Si phase in Mg-Al-Si based magnesium alloys[J]. Hot Working Technology,2007,36(14):71-74.
[3]黄正华,郭学锋,张忠明,等. Si对AZ91D镁合金显微组织与力学性能的影响[J].材料工程,2004(6):28-32.HUANG Zhenghua, GUO Xuefeng, ZHANG Zhongming,et al. Effects of Si on microstructure and mechanical properties of AZ91D magnesium alloy[J]. Journal of Materials Engineering,2004(6):28-32.
[4]黄晓锋,王渠东,刘六法,等.混合稀土对Mg-5Al-1Si组织及性能的影响[J].稀有金属材料与工程,2005,34(5):795-798.HUANG Xiaofeng, WANG Qudong, LIU Liufa, et al.Effect of RE on the microstructure and properties of Mg-5Al-1Si alloy[J]. Rare Metal Materials and Engineering,2005,34(5):795-798.
[5]HU J L,TANG C P,ZHANG X M,et al. Modification of Mg2Si in Mg-Si alloys with neodymium[J]. Transactions of Nonferrous Metals Society of China, 2013, 23(11):3161-3166.
[6] YE L,HU J,TANG C,et al. Modification of Mg2Si in Mg-Si alloys with gadolinium[J]. Materials Characterization,2013,79(1-2):1-6.
[7]杜军,吕信裕,李文芳.稀土Ce对过共晶Mg-Si合金中初生Mg2Si相变质的影响[J].材料工程,2011,41(6):1-4.Du Jun, LV Xinyu, Li Wenfang. Effect of Ce on modification of primary Mg2Si crystals in hypereutectic MgSi alloy[J]. Journal of Materials Engineering,2011,41(6):1-4.
[8]陈淑英,邵秉川,陈智麟,等.铋含量对原位自生Mg2Si/AZ91D复合材料组织与性能的影响[J].有色金属工程,2016,6(3):21-25.CHEN Shuying, SHAO Bingchun, CHEN Zhilin, et al.Influences of Bi content on microstructure and mechanical property of in-situ Mg2Si/AZ91D composites[J]. Nonferrous Metals Engineering,2016,6(3):21-25.
[9]TURNBULL D,VONNEGUT B. Nucleation catalysis[J].Industrial&Engineering Chemistry, 1952, 44(6):1292-1298.
[10] BRAMFITT B L. The effect of carbide and nitride additions on the heterogeneous nucleation behavior of liquid iron[J]. Metallurgical Transactions, 1970, 1(7):1987-1995.
[11]何杰,许振嘉. Ce-Si多层膜中铈硅化物的形成[J].半导体学报,1990,11(12):964-969.HE Jie,XU Zhenjia. Cerium silicide formation in thin CeSi multilayer films[J]. Chinese Journal of Semiconductors,1990,11(12):964-969.
[12]臧树俊,周琦,马勤,等.金属间化合物Mg2Si研究进展[J].铸造技术,2006,27(8):866-870.ZANG Shujun, ZHOU Qi, MA Le, et al. Research progress of intermetallic compound Mg2Si[J]. Foundry Technology,2006,27(8):866-870.
[13] WANG L,GUO E,MA B X. Modification effect of lanthanum on primary phase Mg2Si in Mg-Si alloys[J].Journal of Rare Earths,2008,26(1):105-109.
[14]张忠明,徐春杰,郭学锋,等. Ce、Y、Sb对Mg-9Al-6Si合金中Mg2Si相形貌的影响[J].铸造技术,2009,30(9):1157-1160.ZHANG Zhongming,XU Chunjie,GUO Xuefeng,et al.Effect of modification by cerium,yttrium and antimony on magnesium silicide phases in Mg-9Al-6Si Alloy[J].Foundry Technology,2009,30(9):1157-1160.
[2]杨明波,潘复生,白亮,等.合金元素对Mg-Al-Si系镁合金中Mg2Si相形貌影响的研究进展[J].热加工工艺,2007,36(14):71-74.YANG Mingbo, PAN Fusheng, BAI Liang, et al.Development of effects of alloy elements on morpohoty of Mg2Si phase in Mg-Al-Si based magnesium alloys[J]. Hot Working Technology,2007,36(14):71-74.
[3]黄正华,郭学锋,张忠明,等. Si对AZ91D镁合金显微组织与力学性能的影响[J].材料工程,2004(6):28-32.HUANG Zhenghua, GUO Xuefeng, ZHANG Zhongming,et al. Effects of Si on microstructure and mechanical properties of AZ91D magnesium alloy[J]. Journal of Materials Engineering,2004(6):28-32.
[4]黄晓锋,王渠东,刘六法,等.混合稀土对Mg-5Al-1Si组织及性能的影响[J].稀有金属材料与工程,2005,34(5):795-798.HUANG Xiaofeng, WANG Qudong, LIU Liufa, et al.Effect of RE on the microstructure and properties of Mg-5Al-1Si alloy[J]. Rare Metal Materials and Engineering,2005,34(5):795-798.
[5]HU J L,TANG C P,ZHANG X M,et al. Modification of Mg2Si in Mg-Si alloys with neodymium[J]. Transactions of Nonferrous Metals Society of China, 2013, 23(11):3161-3166.
[6] YE L,HU J,TANG C,et al. Modification of Mg2Si in Mg-Si alloys with gadolinium[J]. Materials Characterization,2013,79(1-2):1-6.
[7]杜军,吕信裕,李文芳.稀土Ce对过共晶Mg-Si合金中初生Mg2Si相变质的影响[J].材料工程,2011,41(6):1-4.Du Jun, LV Xinyu, Li Wenfang. Effect of Ce on modification of primary Mg2Si crystals in hypereutectic MgSi alloy[J]. Journal of Materials Engineering,2011,41(6):1-4.
[8]陈淑英,邵秉川,陈智麟,等.铋含量对原位自生Mg2Si/AZ91D复合材料组织与性能的影响[J].有色金属工程,2016,6(3):21-25.CHEN Shuying, SHAO Bingchun, CHEN Zhilin, et al.Influences of Bi content on microstructure and mechanical property of in-situ Mg2Si/AZ91D composites[J]. Nonferrous Metals Engineering,2016,6(3):21-25.
[9]TURNBULL D,VONNEGUT B. Nucleation catalysis[J].Industrial&Engineering Chemistry, 1952, 44(6):1292-1298.
[10] BRAMFITT B L. The effect of carbide and nitride additions on the heterogeneous nucleation behavior of liquid iron[J]. Metallurgical Transactions, 1970, 1(7):1987-1995.
[11]何杰,许振嘉. Ce-Si多层膜中铈硅化物的形成[J].半导体学报,1990,11(12):964-969.HE Jie,XU Zhenjia. Cerium silicide formation in thin CeSi multilayer films[J]. Chinese Journal of Semiconductors,1990,11(12):964-969.
[12]臧树俊,周琦,马勤,等.金属间化合物Mg2Si研究进展[J].铸造技术,2006,27(8):866-870.ZANG Shujun, ZHOU Qi, MA Le, et al. Research progress of intermetallic compound Mg2Si[J]. Foundry Technology,2006,27(8):866-870.
[13] WANG L,GUO E,MA B X. Modification effect of lanthanum on primary phase Mg2Si in Mg-Si alloys[J].Journal of Rare Earths,2008,26(1):105-109.
[14]张忠明,徐春杰,郭学锋,等. Ce、Y、Sb对Mg-9Al-6Si合金中Mg2Si相形貌的影响[J].铸造技术,2009,30(9):1157-1160.ZHANG Zhongming,XU Chunjie,GUO Xuefeng,et al.Effect of modification by cerium,yttrium and antimony on magnesium silicide phases in Mg-9Al-6Si Alloy[J].Foundry Technology,2009,30(9):1157-1160.