Assessment of the influence of Al-2Nb-2B master alloy on the grain refinement and properties of LM6 (A413) alloy
Assessment of the influence of Al-2Nb-2B master alloy on the grain refinement and properties of LM6 (A413) alloy
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DOI：
10.1016/j.msea.2015.01.053
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发表时间：
2015-03-25
期刊：
影响因子：
6.4
通讯作者：
Babu, N. Hari
中科院分区：
文献类型：
--
作者：
Bolzoni, L.;Nowak, M.;Babu, N. Hari
铸造铝合金是重要的结构材料，但由于缺乏适当的晶粒细化剂，其性能没有得到优化。在这项研究中，添加一种新的铌基晶粒细化剂对LM 6合金（A413）的显微组织特征和力学行为的影响进行了研究。具体地，在大范围的冷却速率（2-100摄氏度/秒）上评估Nb-B孕育的效果。发现Nb基化合物（即，NbB 2和Al 3 Nb）是铝的有效异质形核位点，这导致显微组织特征的显著细化。由于铌硅化物在高得多的温度下形成，因此细化不会受到硅化物形成的阻碍，而当使用Al-Ti-B中间合金时会发生这种情况。结果表明，Al-2Nb-2B中间合金是一种非常有效的细化剂，特别是在慢速冷却条件下，晶粒尺寸的细化可改善合金的性能（均匀的细晶组织、力学性能和孔隙率）。(C)2015作者由爱思唯尔公司出版
Cast aluminium alloys are important structural materials but their performances are not optimised due to the lack of appropriate grain refiners. In this study, the effect of the addition of a novel Nb-based grain refiner on the microstructural features and mechanical behaviour of the LM6 alloy (A413) is studied. Specifically, the effect of Nb-B inoculation is assessed over a great range of cooling rates (2-100 degrees C/s). It is found that Nb-based compounds (i.e., NbB2 and Al3Nb) are potent heterogeneous nucleation sites for aluminium and this leads to a significant refinement of the microstructural features. The refinement is not hindered by the formation of silicides, as it happens when using Al-Ti-B master alloys, because niobium silicides form at much higher temperature. It is concluded that the Al-2Nb-2B master alloy is a very effective refiner especially at slow cooling rate and the refinement of the grain size leads to improved performances (homogeneous fine grain structure, mechanical properties and porosity). (C) 2015 The Authors. Published by Elsevier B.V.