High Performance of T6-Treated Al-15Mg(2)Si-3Cu Composite Reinforced with Spherical Primary Mg2Si after the Co-Modification of Bi plus Sr
High Performance of T6-Treated Al-15Mg(2)Si-3Cu Composite Reinforced with Spherical Primary Mg2Si after the Co-Modification of Bi plus Sr
复制标题
Bi+Sr共改性后球形初生Mg2Si增强T6处理Al-15Mg(2)Si-3Cu复合材料的高性能
DOI：
10.1002/adem.201801119
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发表时间：
2019
影响因子：
3.6
通讯作者：
Wang Zhe
中科院分区：
文献类型：
--
作者：
Chong Xueying;Jiang Wenqiang;Zhao Yuguang;Xu Xiaofeng;Pan Dong;Wang Yitong;Wang Zhe
本文研究了Bi的加入结合T6处理对Sr变质Al-15 Mg 2Si-3Cu复合材料显微组织和拉伸性能的影响。结果表明，Bi的加入进一步提高了Sr对初生Mg 2Si的细化效果。有趣的是，加入0.1%Sr和1%Bi后，得到的初生Mg 2Si为截角八面体，尺寸最小（11.5 μm），与单独加入0.1%Sr后的立方相有明显的不同。因此，作为Mg和Si原子在T6处理过程中强烈扩散的前驱体，截顶八面体初生Mg 2Si在500 °C固溶6 h后完全转变为球形，球度最高（0.92）。此外，进一步的结果表明，Sr + Bi的共变质不仅在促进初生Mg 2Si的球化方面更有效，而且在获得细小的点状共晶Mg 2Si方面比Sr或Bi的单一变质更有效。结果，抗拉强度和伸长率分别显著提高到374 MPa和4.75%。因此，本研究提供了一种与T6处理相结合的共变质体系来合成球形初生Mg 2Si，有助于制备高性能的Al-Mg 2Si复合材料。
In this work, the effect of the addition of Bi combined with T6 treatment on microstructure and tensile properties of Sr‐modified Al–15Mg2Si–3Cu composite is investigated. The results show that the refinement effect of Sr on primary Mg2Si is further enhanced via the combined addition of Bi. Interestingly, the truncated octahedral primary Mg2Si with the smallest size (11.5 μm) is obtained by adding 0.1% Sr and 1% Bi, which is distinctly different from the cubic shape modified by single 0.1% Sr. Consequently, as a precursor with strong diffusion of Mg and Si atoms during T6 treatment, the truncated octahedral primary Mg2Si is completely transformed into spherical morphology with the highest sphericity (0.92) solution treated at 500 °C for 6 h. Additionally, further results reveal that the co‐modification of Sr + Bi is more efficient not only in promoting the spheroidization of primary Mg2Si, but also obtaining the fine dot‐like eutectic Mg2Si than single modification of Sr or Bi. As a result, the tensile strength and elongation are significantly enhanced to 374 MPa and 4.75%, respectively. Thereby, this work offers an alternative co‐modification system combined with T6 treatment to synthesize the spherical primary Mg2Si, which is helpful to prepare the high performance Al–Mg2Si composite.