Evaluation of the block boundary and sub-block boundary strengths of ferrous lath martensite using a micro-bending test
Evaluation of the block boundary and sub-block boundary strengths of ferrous lath martensite using a micro-bending test
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DOI：
10.1016/j.msea.2010.08.026
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发表时间：
2010-11-15
期刊：
影响因子：
6.4
通讯作者：
Higo, Yakichi
中科院分区：
文献类型：
--
作者：
Shibata, Akinobu;Nagoshi, Takashi;Higo, Yakichi
本文报道了我们通过微弯试验对板条马氏体的块状边界和亚块状边界强度的研究。亚块界对板条马氏体的宏观强度贡献很小。相反，试件中块体边界的存在大大提高了强度。此外，在荷载-位移曲线中，块体边界引起了屈服后的锯齿状流动和荷载下降。载荷下降和锯齿状流动可归因于位错的堆积和随后的位错跨越块体边界的传播。在对变形后的样品进行显微组织观察时，我们发现块体边界对位错的运动有明显的限制作用，而亚块体边界对位错的运动没有明显的限制作用。结果表明，块状晶界是板条马氏体强度的最有效晶界。(C)2010爱思唯尔B.V.保留所有权利。
We report our investigation of the block boundary and sub-block boundary strengths of lath martensite evaluated through a micro-bending test. The sub-block boundaries contribute very little to the macroscopic strength of the lath martensite. In contrast, the presence of a block boundary in the specimen greatly increased the strength. In addition, the block boundary induced a serrated flow and load drop after yielding in the load-displacement curve. The load drop and serrated flow were attributable to dislocation pile-up and subsequent propagation of dislocations across the block boundary. In a microstructural observation of specimens after deformation, we found that a block boundary significantly restricts the motion of dislocations, while a sub-block boundary does not. We concluded that the block boundary is the most effective grain boundary for strength in lath martensite. (C) 2010 Elsevier B.V. All rights reserved.