The natural aging and precipitation hardening behaviour of Al-Mg-Si-Cu alloys with different Mg/Si ratios and Cu additions
The natural aging and precipitation hardening behaviour of Al-Mg-Si-Cu alloys with different Mg/Si ratios and Cu additions
复制标题
不同Mg/Si比和Cu添加量的Al-Mg-Si-Cu合金的自然时效和沉淀硬化行为
DOI：
10.1016/j.msea.2014.12.086
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发表时间：
2015-03-11
期刊：
影响因子：
6.4
通讯作者：
Yang, Guang
中科院分区：
文献类型：
--
作者：
Ding, Lipeng;Jia, Zhihong;Yang, Guang
采用维氏显微硬度计、差示扫描量热仪（DSC）和透射电镜（TEM）研究了不同Mg/Si比和Cu含量的Al-Mg-Si-Cu合金的自然时效和人工时效行为。在自然时效和人工时效过程中，过量的Si和Cu的加入提高了合金的硬化能力。在人工时效过程中，低Cu和高Si含量的合金比富Mg合金具有更高的沉淀硬化。相比之下，具有高量的Cu的合金在沉淀硬化期间较少依赖于Mg/Si比，这是由于它们相似的时效动力学。对峰值时效硬度有贡献的主要析出相是L、Q'和β“相。在过时效条件下，由于L相的优先析出，富Mg和Cu的合金比富Si的合金具有更细和更多的析出物。过量的Mg和高Cu的结合导致合金在T4回火状态下具有相对较低的硬度，而在油漆烘烤循环后具有相对较高的硬度。因此，该合金在汽车覆盖件应用中具有良好的潜力。(C)© 2014 Elsevier B. V.保留所有权利。
The natural aging and artificial aging behaviours of Al-Mg-Si-Cu alloys with different Mg/Si ratios and Cu additions were investigated using Vickers microhardness measurements, differential scanning calorimetry (DSC) analysis and transmission electron microscopy (TEM) characterisation. Excess Si and Cu additions enhanced the alloy hardening ability during natural (NA) and artificial aging (AA). Alloys with low Cu and high Si contents exhibited higher precipitation hardening than alloys rich in Mg during artificial aging. In contrast, the alloys with high amounts of Cu were less dependent on the Mg/Si ratio during precipitation hardening due to their similar aging kinetics. The main precipitate phases that contributed to the peak-aging hardness were the L, Q' and beta '' phases. In the over-aging conditions, the alloys rich in Mg and Cu had finer and more numerous precipitates than their Si-rich equivalents due to the preferential precipitation of the L phase. The combination of excess Mg and high Cu resulted in an alloy with a relatively low hardness in T4 temper and a relatively higher hardness after the paint baking cycle. Thus, this alloy has good potential for use in auto body panel applications. (C) 2014 Elsevier B.V. All rights reserved.