High damping capacity of ultra-fine grained aluminum produced by accumulative roll bonding
High damping capacity of ultra-fine grained aluminum produced by accumulative roll bonding
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DOI：
10.1016/s0925-8388(03)00265-2
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发表时间：
2003-06-30
影响因子：
6.2
通讯作者：
Ota, K
中科院分区：
文献类型：
--
作者：
Koizumi, Y;Ueyama, M;Ota, K
累积轧制复合（ARB）是一种可以制备具有超细（亚微米）晶粒组织的高强度金属材料的剧烈塑性变形工艺。通过这种方法生产的金属也有望显示出优异的阻尼能力，因为它们含有大量的晶格缺陷，这些缺陷会引起内部摩擦。我们研究了高纯度（99.99%Al）和商业纯度（99%Al）铝片ARB处理到等效应变为4的阻尼能力。99.99%Al和99%Al的内耗值（Q（-1））分别高达12 × 10（-3）和6 × 10（-3）。微观结构进行了观察，以澄清阻尼机制。99.99%Al和99%Al的饼状超细晶的平均晶粒厚度分别为640和250 nm。在两种ARB处理的铝板中的超细晶粒内观察到显著量的位错。高阻尼能力归因于位错的振动，其末端与晶界紧密结合。(C)2003 Elsevier Science B. V.保留所有权利。
Accumulative rolling bonding (ARB) is a kind of severe plastic deformation process which can produce high strength metals with ultrafine (sub-micron) grained microstructure. Metals produced by this process are also expected to show excellent damping capacity since they contain significant amounts of lattice defects which give rise to internal friction. We examined the damping capacity of high purity (99.99% Al) and commercial purity (99% Al) aluminum sheets ARB processed to an equivalent strain of 4. Internal friction values (Q(-1)) of the 99.99% Al and the 99% Al were as high as 12X10(-3) and 6X10(-3), respectively. Microstructures were observed to clarify the damping mechanism. The mean grain thickness of the pancake-like shaped ultrafine grains were 640 and 250 nm in 99.99% Al and 99% Al, respectively. A significant amount of dislocations was observed within the ultrafine grains in both of the ARB-processed aluminum sheets. The high damping capacity was attributed to vibration of the dislocations whose ends were tightly bound with the grain boundaries. (C) 2003 Elsevier Science B.V. All rights reserved.