研究添加0.1%～2.0%Ba(质量分数,下同)对高Si原位自生Mg_2Si/Mg-Zn-Si复合材料组织和力学性能的影响.结果表明:随着Ba含量的增加,初生Mg_2Si由树枝晶转变为多面体颗粒,其尺寸先减小后增大;汉字状共晶Mg_2Si也先减少后增加;复合材料的力学性能显著改善.当Ba含量为1.0%时,其细化变质效果最好,合金的综合力学性能最佳,这是由于Ba的加入形成了大量细微的BaMg_2Si_2粒子可作为初生Mg_2Si的异质形核核心,从而细化变质了Mg_2Si;当Ba含量过高(>1.0%),BaMg_2Si_2相聚集长大导致了过变质现象,力学性能下降.变质为细小多边形的Mg_2Si颗粒减少了加载时应力集中与裂纹产生、扩展;其弥散分布阻碍了变形时位错运动,因此强化了复合材料.
Effects of 0.1%-2.0%(mass fraction) Ba addition on the microstructure and tensile properties of Mg_2Si/Mg-Zn-Si composites with high Si content were investigated.The results indicate that, the morphology of primary Mg_2Si in the composites changes from large dendrite to fine polygonal with the increasing Ba content, and its average size sharply decreases until addition of Ba 1.0% and then slowly increases.The average size of eutectic Mg_2Si also shows the same change trend.Numerous tiny BaMg_2Si_2 particles act as the heterogeneous nucleation substrate for primary Mg_2Si.It is also found that BaMgV2Si_2 size in Mg_2Si is obviously coarsened as addition of Ba surpasses 1.0%, which is responsible for over modification.Refined Mg_2Si particles dispersion-strengthen the composite and results in the improvement of ductility.The proper Ba content is a key factor to obtain effectively refined Mg_2Si and enhanced composite.
参考文献
| [1] | L. Lu;K.K. Thong;M. Gupta .Mg-based composite reinforced by Mg_2Si[J].Composites science and technology,2003(5):627-632. |
| [2] | Ritsuko Tsuzuki;Katsuyoshi Kondoh .In Situ Solid-State Synthesis of Mg Composite with Mg_2Si Dispersoids[J].Materials Science Forum,2005(Pt.1):497-500. |
| [3] | Kazunori Asano;Hiroyuki Yoneda .In Situ Formation and Refinement of Mg_2Si in Fiber-Reinforced AZ91D Magnesium Alloy[J].Materials transactions,2007(6):1469-1475. |
| [4] | S. K. Thakur;H. Dieringa;B. K. Dhindaw .THERMAL CYCLING AND CREEP STUDIES OF AM50 + Nd MAGNESIUM ALLOY BASED CARBON FIBER, SiC PARTICULATE AND IN-SITU Mg_2Si REINFORCED HYBRID COMPOSITES[J].Transactions of the Indian Institute of Metals,2005(4):653-659. |
| [5] | LU L;LAI M O;HOE M L .Formation of nanocrystalline Mg_2Si and Mg2Si dispersion strengthened Mg-Al alloy by mechanical alloying[J].Nano-Structured Materials,1998,10(04):551-563. |
| [6] | B. L. Mordike .Development of highly creep resistant magnesium alloys[J].Journal of Materials Processing Technology,2001(3):391-394. |
| [7] | Yichuan Pan;Xiangfa Liu;Hua Yang .Microstractural formation In a hypereutectic Mg-Si alloy[J].Materials Characterization,2005(3):241-247. |
| [8] | M. MABUCHI;K. HIGASHI .STRENGTHENING MECHANISMS OF Mg-Si ALLOYS[J].Acta materialia,1996(11):4611-4618. |
| [9] | Ritsuko Tsuzuki;Katsuyoshi Kondoh;Wenbo Du .Effect of Extrusion Conditions on Properties of Hot Extruded Mg Composite with Mg_2Si Dispersions via Solid-state Synthesis[J].Materials Science Forum,2003(Pt.2):789-794. |
| [10] | Jiang QC;Wang HY;Wang Y;Ma BX;Wang JG .Modification of Mg2Si in Mg-Si alloys with yttrium[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2005(1/2):130-135. |
| [11] | H.Y. Wang;Q.C. Jiang;B.X. Ma .Modification of Mg_2Si in Mg-Si alloys with K_2TiF_6, KBF_4 and KBF_4 + K_2TiF_6[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2005(1/2):105-108. |
| [12] | GUO E J;MA B X;WANG L P .Modification of Mg_2Si morphology in Mg-Si alloys with Bi[J].Journal of Materials Processing Technology,2008,206(1-3):161-166. |
| [13] | 李金锋,耿浩然,滕新营.Ba对AZ91镁合金组织和性能的影响[J].热加工工艺,2005(07):5-7,36. |
| [14] | Lihua Liao;Xiuqing Zhang;Haowei Wang .Influence of Sb on damping capacity and mechanical properties of Mg_2Si/Mg-9Al composite materials[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2007(1/2):292-296. |
| [15] | Jongjin Jeon;Sangwon Lee;Byeongho Kim .Effect of Sb and Sr Addition on Corrosion Properties of Mg-5Al-2Si Alloy[J].Journal of the Korean Institute of Metals and Materials,2008(5):304-309. |
| [16] | BRAMFITT B L .The effect of carbide and nitride additions on the heterogenous nucleation behavior of liquid iron[J].Metallurgical and Materials Transactions,1970,1(07):197-201. |
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