Microstructural development of Al-15wt.%Mg2Si in situ composite with mischmetal addition
Microstructural development of Al-15wt.%Mg2Si in situ composite with mischmetal addition
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DOI：
10.1016/s0921-5093(99)00732-7
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发表时间：
2000-04
期刊：
影响因子：
6.4
通讯作者：
Junjia Zhang;Z. Fan;Y. Q. Wang;B. Zhou
中科院分区：
文献类型：
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作者：
Junjia Zhang;Z. Fan;Y. Q. Wang;B. Zhou
原位Al-Mg 2Si复合材料作为一类新型的航空航天等先进工程应用超轻材料，越来越受到材料科学家和设计工程师的关注。在我们以前的工作中已经证明，通过适当的显微组织控制，原位Al-Mg_2Si复合材料可以提供非常有前途的强度、塑性和断裂韧性的组合。本文研究了混合稀土（MM，稀土元素的混合物）对Al-15 wt.%原位凝固组织的影响。研究了Mg 2Si复合材料。结果表明，随着MM添加量的增加，初生Mg 2Si颗粒尺寸明显减小，假共晶Mg 2Si由纤维状变为片状，呈现离异特征。由于MM的加入，形成了少量的Al 11 RE 3形式的含RE化合物。研究表明，添加MM对初生Mg 2Si颗粒的形核过程以及随后的α-Al相和伪共晶基体的形成具有重要影响。
In situ Al–Mg2Si composites, as a new class of ultralight materials for aerospace and other advanced engineering applications, are attracting more and more attention of both material scientists and design engineers. It has been demonstrated in our previous work that with proper microstructural control, in situ Al–Mg2Si composites can offer very promising combinations of strength, ductility and fracture toughness. In the present work, the effects of mischmetal (MM, a mixture of rare-earth, RE elements) additions on the microstructural development of an in situ Al–15wt.%Mg2Si composite were investigated. It was found that with increasing MM additions in the composites, the size of primary Mg2Si particles was considerably reduced, and that the pseudo-eutectic Mg2Si was changed from a fibrous morphology to a flake-like morphology, showing a divorced character. A small amount of RE-containing compounds in the form of Al11RE3were formed as a result of MM additions. It is believed that MM additions have a strong influence on the nucleation process of primary Mg2Si particles and the subsequent formation of the α-Al phase and the pseudo-eutectic matrix.