Ca含量对AZ91-2Sm镁合金组织和力学性能的影响
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摘要
采用光学显微镜、扫描电镜(SEM)、X射线衍射仪(XRD)和电子万能材料实验机,研究了Ca含量(0%～2.4wt%)对AZ91-2Sm镁合金组织和力学性能的影响。结果表明,适量Ca的加入能细化AZ91-2Sm合金的晶粒,改善合金的组织;同时合金中出现高熔点、稳定性好的亮白色的块状Al2Sm和沿Mg17Al12相分布的Al2Ca相。在室温和高温(150、175℃)下,合金的抗拉强度和伸长率均随Ca含量的变化而变化,其中当w (Ca)=1.6%时,抗拉强度相比AZ91-2Sm增加了15.48%(室温)、8.03%(150℃)、2.66%(175℃),伸长率提高了32.86%(室温)、22.72%(175℃),但在150℃时伸长率相比AZ91-2Sm的下降8.78%。
The effects of Ca content(0%-2.4 wt%) on the microstructure and mechanical properties of AZ91-2 Sm magnesium alloy were investigated by optical microscope, scanning electron microscopy(SEM), X-ray diffraction(XRD) and electronic universal material testing machine. The results show that the proper addition of Ca can refine the grains of AZ91-2 Sm and improve the microstructure of the alloy. At the same time, the bright white Al2 Sm with high melting point and good stability and Al2 Ca phase along Mg17 Al12 phase appears in the alloy. The tensile strength and elongation of the alloy change with the increase of Ca content at room temperature and high temperature 150 ℃ and 175 ℃. Compared with that of AZ91-2 Sm, the tensile strength of the alloy increases by 15.48%(room temperature), 8.03%(150 ℃), 2.66%(175 ℃), the elongation increases 32.86%(room temperature) and 22.72%(175 ℃) respectively when w(Ca) =1.6%. However, the elongation at 150℃ is 8.78% lower than that of AZ91-2 Sm.
The effects of Ca content(0%-2.4 wt%) on the microstructure and mechanical properties of AZ91-2 Sm magnesium alloy were investigated by optical microscope, scanning electron microscopy(SEM), X-ray diffraction(XRD) and electronic universal material testing machine. The results show that the proper addition of Ca can refine the grains of AZ91-2 Sm and improve the microstructure of the alloy. At the same time, the bright white Al2 Sm with high melting point and good stability and Al2 Ca phase along Mg17 Al12 phase appears in the alloy. The tensile strength and elongation of the alloy change with the increase of Ca content at room temperature and high temperature 150 ℃ and 175 ℃. Compared with that of AZ91-2 Sm, the tensile strength of the alloy increases by 15.48%(room temperature), 8.03%(150 ℃), 2.66%(175 ℃), the elongation increases 32.86%(room temperature) and 22.72%(175 ℃) respectively when w(Ca) =1.6%. However, the elongation at 150℃ is 8.78% lower than that of AZ91-2 Sm.
引文
[1] Ding Wenjiang.The science and technology of magnesium alloy[M].Beijing Science Press,2007.
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[5] Son H T, Lee J S, Kim D G, et al.Effects of samarium(Sm)additions on the microstructure and mechanical properties of as-cast and hot-extruded Mg-5wt%Al-3wt%Ca-based alloys[J].Journal of Alloys and Compounds,2009,473(1/2):446-452.
[6] Li K J, Li Q A, Jing X T, et al.Effects of Sb, Sm and Sn additions on the microstructure and mechanical properties of Mg-6A1-1.2Y-0.9Nd alloy[J].Rare Meta1s,2009,28(5):516-522.
[7] Kinji Hirai, Hidetoshi Somekawa, Yorinobu Takigawa, et al.Effects of Ca and Sr addition on mechanical properties of a cast AZ91 magnesium alloy at room and elevated temperature[J].Materials Science and Engineering A,2005,403:276-280.
[2]徐广龙,袁晓黎,刘立斌.Mg-Al-Zn-Sm合金的组织、力学性能及其热力学分析[J].中国有色金属学报,2012,22(5):1255-1261.
[3]李杰华,杨光昱.耐热铸造镁合金的研究现状及其发展趋势[J].中国铸造装备与技术,2007(2):2-6.
[4] Wang Q D, Chen W Z, Zeng X Q, et al.Effects of Ca addition on the microstructure and mechanical properties of AZ91 magnesium alloy[J].Journal of Materials Science,2001,36(12):3035-3040.
[5] Son H T, Lee J S, Kim D G, et al.Effects of samarium(Sm)additions on the microstructure and mechanical properties of as-cast and hot-extruded Mg-5wt%Al-3wt%Ca-based alloys[J].Journal of Alloys and Compounds,2009,473(1/2):446-452.
[6] Li K J, Li Q A, Jing X T, et al.Effects of Sb, Sm and Sn additions on the microstructure and mechanical properties of Mg-6A1-1.2Y-0.9Nd alloy[J].Rare Meta1s,2009,28(5):516-522.
[7] Kinji Hirai, Hidetoshi Somekawa, Yorinobu Takigawa, et al.Effects of Ca and Sr addition on mechanical properties of a cast AZ91 magnesium alloy at room and elevated temperature[J].Materials Science and Engineering A,2005,403:276-280.