The effect of dispersoids on the grain refinement mechanisms during deformation of aluminium alloys to ultra-high strains
The effect of dispersoids on the grain refinement mechanisms during deformation of aluminium alloys to ultra-high strains
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DOI：
10.1016/j.actamat.2004.09.042
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发表时间：
2005-01-01
期刊：
影响因子：
9.4
通讯作者：
Prangnell, PB
中科院分区：
文献类型：
--
作者：
Apps, PJ;Berta, M;Prangnell, PB
研究了细弥散相对铝合金大变形过程中晶粒细化机制和细化速率的影响。采用等通道转角挤压方法对Al-0.2Sc二元合金进行了有效应变为10的变形，合金中含有直径约为20 nm，间距约为100 nm的共格Al 3Sc弥散相。由此产生的变形结构进行了定量分析，使用高分辨率的电子背散射衍射取向映射，并将结果进行了比较，从单相Al-0.13Mg合金，在相同的条件下变形。精细的，不可剪切的，分散体的存在下，已被发现均匀滑移，延迟形成的蜂窝子结构，并抑制变形过程中的微剪切带的形成。这些因素联合收割机降低了在低至中等应变下高角度晶界的产生速率，因此，在剧烈变形期间，延迟了亚微米晶粒结构至更高应变的形成。(C)2004 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The effect of fine dispersoids on the mechanisms and rate of grain refinement has been investigated during the severe deformation of a model aluminium alloy. A binary Al-0.2Sc alloy, containing coherent Al3Sc dispersoids, of similar to20 nm in diameter and similar to100 nm spacing, has been deformed by equal channel angular extrusion to an effective strain of ten. The resulting deformation structures were quantitatively analysed using high-resolution electron backscattered diffraction orientation mapping, and the results have been compared to those obtained from a single-phase Al-0.13Mg alloy, deformed under identical conditions. The presence of fine, nonshearable, dispersoids has been found to homogenise slip, retard the formation of a cellular substructure and inhibit the formation of microshear bands during deformation. These factors combine to reduce the rate of high-angle grain boundary generation at low to medium strains and, hence, retard the formation of a submicron grain structure to higher strains during severe deformation. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.