Precipitation strengthening of aluminum alloys by room-temperature cyclic plasticity
Precipitation strengthening of aluminum alloys by room-temperature cyclic plasticity
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DOI：
10.1126/science.aav7086
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发表时间：
2019-03-01
期刊：
影响因子：
56.9
通讯作者：
Hutchinson, Christopher
中科院分区：
文献类型：
--
作者：
Sun, Wenwen;Zhu, Yuman;Hutchinson, Christopher
高强度铝合金对轻量化车辆非常重要，被广泛用于飞机和越来越多的汽车中。最高强度的铝合金需要一系列的高温“烘焙”(120摄氏度到200摄氏度)，才能通过固相沉淀形成高密度的纳米颗粒。我们发现，可控的室温循环变形足以连续地向材料中注入空位，并调节非常细小(1-2纳米)分布的溶质团簇的动态析出。这导致了比传统热处理更好的材料强度和延伸率性能，尽管加工时间要短得多。所形成的显微组织比传统热处理的组织更加均匀，没有出现无沉淀区。因此，这些合金可能更耐损坏。
High-strength aluminum alloys are important for lightweighting vehicles and are extensively used in aircraft and, increasingly, in automobiles. The highest-strength aluminum alloys require a series of high-temperature "bakes" (120 degrees to 200 degrees C) to form a high number density of nanoparticles by solid-state precipitation. We found that a controlled, room-temperature cyclic deformation is sufficient to continuously inject vacancies into the material and to mediate the dynamic precipitation of a very fine (1-to 2-nanometer) distribution of solute clusters. This results in better material strength and elongation properties relative to traditional thermal treatments, despite a much shorter processing time. The microstructures formed are much more uniform than those characteristic of traditional thermal treatments and do not exhibit precipitate-free zones. These alloys are therefore likely to be more resistant to damage.