Grain Boundary Segregation in UFG Alloys Processed by Severe Plastic Deformation
Grain Boundary Segregation in UFG Alloys Processed by Severe Plastic Deformation
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DOI：
10.1002/adem.201200060
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发表时间：
2012-11-01
影响因子：
3.6
通讯作者：
Valiev, Ruslan
中科院分区：
文献类型：
--
作者：
Sauvage, Xavier;Ganeev, Artur;Valiev, Ruslan
采用原子探针层析技术研究了大塑性变形（SPD）条件下AlMg合金、碳钢和Armco（R）Fe的晶界偏聚。在非变形状态下，铝合金的GB是Mg贫化的，但在SPD之后检测到高达20原子%的一些局部富集。在铁基合金中，SPD后沿沿着晶界也表现出大的碳浓度。这些实验观察结果归因于特定的结构的GB通常被描述为非平衡的超细晶粒材料加工的SPD。讨论并比较了置换型（Mg在fcc Al中）和间隙型（C在bcc Fe中）溶质原子的GB偏析机制。
Grain boundary (GB) segregations were investigated by atom probe tomography in an AlMg alloy, a carbon steel and Armco (R) Fe processed by severe plastic deformation (SPD). In the non-deformed state, the GBs of the aluminum alloy are Mg depleted, but after SPD some local enrichment up to 20 at% was detected. In the Fe-based alloys, large carbon concentrations were also exhibited along GBs after SPD. These experimental observations are attributed to the specific structure of GBs often described as non-equilibrum in ultra fine grained materials processed by SPD. The GB segregation mechanisms are discussed and compared in the case of substitutional (Mg in fcc Al) and interstitial (C in bcc Fe) solute atoms.