采用光学显微镜(OM)、带能谱分析(EDAX)的扫描电子显微镜(SEM)、X射线衍射仪(XRD)等方法对Mg-11Y-5Gd-2Zn-0.5Zr(WGZ115)合金的原始铸态(F态)、固溶处理态(T4态)和峰值时效态(T6态)的组织结构进行了分析.研究表明:F态WGZ115合金主要由基体(α-Mg)、晶间共晶相(Mg_(24)(YGdZn)_5)和长周期结构相(Mg_(12)Y_1Zn_1)组成.T4态WGZ115合金主要由基体相(α-Mg)、长周期结构相(Mg_(12)Y_1Zn_1)和少量分布于晶界附近的方块相(Mg-Y-Gd方块相)组成.T6态WGZ115合金的形貌与T4态相似,圆形的富Zr相始终存在于三种状态的合金中.通过不同温度下的拉伸实验发现T4态WGZ115合金的抗拉强度和塑性好于F态合金.而T6态合金的力学性能最好,在200℃时抗拉强度达到最大值341.1MPa.
Microstructures of as-cast(F),solution treatmented (cast-T4) and aging treatmented (cast-T6) Mg-11Y-5Gd-2Zn-0.5Zr(WGZ115) alloy were investigated using optical microscopy (OM),scanning electron microscopy (SEM) with energy dispersive X-ray analyses (EDAX) and X-ray diffractometry (XRD).The results show that the as-cast alloy is consisted of α-Mg,eutectic phase (Mg_(24) (YGdZn)_5) and needle-and plate-shaped long-period structure(Mg_(12) Y_1 Zn_1).After solution treatment the WGZ115 alloy is consisted of α-Mg,LPSO phase and cube-shaped phases (cuboid Mg-Y-Gd) around the grain boundary.The microstructure of WGZ115 alloy after aging treatment is similar to that of solution treatment.Some Zr-rich cores exist in the as-cast,cast-T4 and cast-T6 samples.At different temperatures,the tensile properties of the as-cast WGZ115 alloy are the worst.The cast-T4 alloy has better strength and plastic performance than those of as-cast alloy.The cast-T6 alloy exhibits the best tensile properties with the maximum ultimate tension strength of 341.1MPa at 200℃.
参考文献
| [1] | 李德辉,董杰,曾小勤,卢晨,丁文江.高性能稀土镁合金研究进展[J].材料导报,2005(08):51-54. |
| [2] | E. Abe;Y. Kawamura;K. Hayashi .Long-period ordered structure in a high-strength nanocrystalline Mg-1 at percent Zn-2 at percent Y alloy studied by atomic-resolution Z-contrast STEM[J].Acta materialia,2002(15):3845-3857. |
| [3] | T. Itoi;T. Seimiya;Y. Kawamura;M. Hirohashi .Long period stacking structures observed in Mg_(97)Zn_1Y_2 alloy[J].Scripta materialia,2004(2):107-111. |
| [4] | 张松,袁广银,卢晨,丁文江.长周期结构增强镁合金的研究进展[J].材料导报,2008(02):61-63,81. |
| [5] | 童炎 .冷却速度及热处理工艺对Mg-Y-Gd-Zn系合金显微组织和力学性能的影响[D].上海交通大学,2008. |
| [6] | Luo ZP.;Zhang SQ. .High-resolution electron microscopy on the X-Mg12ZnY phase in a high strength Mg-Zn-Zr-Y magnesium alloy[J].Journal of Materials Science Letters,2000(9):813-815. |
| [7] | S.M. He;X.Q. Zeng;L.M. Peng .Microstructure and strengthening mechanism of high strength Mg-10Gd-2Y-0.5Zr alloy[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2007(1/2):316-323. |
| [8] | M. Nishida;Y. Kawamura;T. Yamamuro .Formation process of unique microstructure in rapidly solidified Mg_(97)Zn_1Y_2 alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2004(0):1217-1223. |
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