Consideration of particle-strengthening mechanism of copper-precipitation-strengthened steels by atom probe tomography analysis
Consideration of particle-strengthening mechanism of copper-precipitation-strengthened steels by atom probe tomography analysis
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DOI：
10.1016/j.msea.2011.12.056
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发表时间：
2012-02-15
期刊：
影响因子：
6.4
通讯作者：
Kobayashi, Y.
中科院分区：
文献类型：
--
作者：
Takahashi, J.;Kawakami, K.;Kobayashi, Y.
采用原子探针层析成像（APT）分析了铜强化钢的析出铜颗粒的强化机理。通过对不同时效时间加铜钢的拉伸试验和平均颗粒间距的估算，研究了颗粒直径对每铜颗粒相互作用（阻力）力的依赖关系。随着颗粒直径的增大，作用力在3 nm以下急剧增大，在4 nm以上逐渐增大。另一方面，在直径约4 ~ 6 nm处观察到相干bcc向半相干9R铜粒子的转变。晶粒直径与相互作用力的关系表明，颗粒增强的主要机制是铜颗粒与铁基体之间弹性模量的差异，而不是相干bcc铜颗粒的错配应变。结果还表明，粒径、数量密度、体积分数和相互作用力之间的平衡产生了最大颗粒强化区域。(C) 2011 Elsevier B.V.版权所有
Atom probe tomography (APT) analysis of copper-strengthened steels was performed to elucidate the strengthening mechanism due to precipitated copper particles. The dependence of the particle diameter on the interaction (resistance) force per copper particle was examined by performing tensile tests and estimating the mean particle spacing in copper-added steels with various aging times. With increasing particle diameter, the interaction force dramatically increased below 3 nm and then gradually increased above 4 nm. On the other hand, the transformation of coherent bcc to semi-coherent 9R copper particles was observed at a diameter of approximately 4-6 nm. The dependence of the diameter on the interaction force indicates that the main mechanism of particle strengthening is due to the difference in elastic modulus between the copper particles and the iron matrix, and not the misfit strains of coherent bcc copper particles. The results also show that the balance between the diameter, number density, volume fraction and interaction force produced the region of maximum particle strengthening. (C) 2011 Elsevier B.V. All rights reserved.