High tensile ductility via enhanced strain hardening in ultrafine-grained Cu
High tensile ductility via enhanced strain hardening in ultrafine-grained Cu
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DOI：
10.1016/j.msea.2011.10.070
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发表时间：
2012-01
期刊：
影响因子：
6.4
通讯作者：
P. Xue;B. Xiao;Z. Ma
中科院分区：
文献类型：
--
作者：
P. Xue;B. Xiao;Z. Ma
由于应变硬化不足而导致的低拉伸塑性是超细晶材料的主要缺陷，这限制了其实际应用。在这里，通过一个简单的摩擦搅拌加工技术与额外的冷却，我们准备UFG铜具有高强度和拉伸延展性。增强的应变硬化能力，这是有效的阻挡和积累位错，实现在本再结晶UFG显微组织。提高应变硬化能力的主要原因是位错密度低，大部分的大角度晶界和一定数量的共格孪晶界的存在。为设计具有良好力学性能的超细粉末材料提供了一种策略。
Low tensile ductility owing to the insufficient strain hardening is the main drawback for ultrafine-grained (UFG) materials, which restricts their practical applications. Here, via a simple friction stir processing technique with additional cooling, we prepared UFG Cu with high strength and tensile ductility. Enhanced strain hardening capacity, which is effective in blocking and accumulating dislocations, was achieved in the present recrystallized UFG microstructure. The enhanced strain hardening capacity is attributed primarily to the low dislocation density, and the presence of large fraction of high angle grain boundaries and a certain amount of coherent twin boundaries. This work provides a strategy for designing UFG materials with good mechanical properties.