Nanoprecipitation of oxide particles and related high strength in oxide-dispersion-strengthened iron-aluminium-chromium intermetallics
Nanoprecipitation of oxide particles and related high strength in oxide-dispersion-strengthened iron-aluminium-chromium intermetallics
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DOI：
10.1016/j.actamat.2013.04.034
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发表时间：
2013-07
期刊：
影响因子：
9.4
通讯作者：
D. G. Morris;M. A. Muñoz-Morris
中科院分区：
文献类型：
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作者：
D. G. Morris;M. A. Muñoz-Morris
采用机械合金化技术制备了一系列氧化物弥散硬化的Fe-Al-Cr铁基铝化物，其成分介于二元Fe-Al合金和工业Fe-Cr合金之间。超细氧化物粒子在B2有序基质中的{100}面上析出，最初是亚稳的面心立方Y2O3相，后来转变为单斜晶系Al2Y4O9的富铝相。讨论了这种沉淀序列在确定颗粒大小和密度方面的重要性。对高温下的力学性能进行了测试，发现强度主要取决于细小颗粒的贡献，也取决于细小颗粒尺寸和有序基质的贡献。强调了受合金成分强烈影响的弹性模数变化和基质强度变化在决定材料强度中的作用。通过对决定颗粒形核率和高温强度的因素的分析，制定了改善组织细化和强度的预测规则。
A series of oxide-dispersion-hardened Fe–Al–Cr iron aluminides has been prepared by mechanical alloying techniques producing compositions intermediate between binary Fe–Al and commercial Fe–Cr alloys. The very fine oxide particles form by precipitation on the {100} planes in the B2 ordered matrix, initially as a metastable face-centred cubic Y2O3phase which later transforms to an Al-richer phase with monoclinic Al2Y4O9structure. The importance of this precipitation sequence in determining particle size and density is discussed. Mechanical properties are examined up to high temperatures, and strength is shown to depend mostly on the contribution of the fine particles, with also contributions from the fine grain size, and from the ordered matrix. The roles of elastic modulus variations, strongly affected by alloy composition, and of matrix strength variations in determining material strength are emphasized. Analysis of the factors determining particle nucleation rate and high-temperature strength leads to the development of predictive rules for improving microstructural refinement and strength.