On the origin of strengthening mechanisms in Ni-Mo alloys prepared via powder metallurgy
On the origin of strengthening mechanisms in Ni-Mo alloys prepared via powder metallurgy
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DOI：
10.1016/j.matdes.2016.10.024
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发表时间：
2017-01-05
影响因子：
8.4
通讯作者：
Zhou, Xingtai
中科院分区：
文献类型：
--
作者：
Yang, Chao;Muransky, Ondrej;Zhou, Xingtai
在熔盐核反应堆中，除了利用纳米沉淀物进行沉淀强化外，还利用碳化硅颗粒的分散强化，开发出了一种新型材料。采用机械合金化（MA）、火花等离子烧结（SPS）、快速冷却、高温退火和水淬等工艺，制备了不同SiC含量（0.5 ~ 2.5 wt.%）的分散沉淀强化（DPS）镍基合金电池。利用实验室x射线衍射（XRD）、电子背散射衍射（EBSD）和透射电子显微镜（TEM）对新型合金进行了微观组织表征。结果表明，在烧结/退火过程中析出的纳米ni3si析出物和初始粉末混合物中的SiC弥散能有效增强合金的NiMo基体。此外，Mo在Ni中的固溶体强化了基体。因此，这些新开发的NiMo合金具有弥散、析出和固溶强化的优点，从而具有优异的力学性能。(C) 2016 Elsevier Ltd.版权所有。
A new class of materials, which rely on the dispersion strengthening of SiC particles in addition to precipitation strengthening by nano-precipitates is being developed for the application in molten salt nuclear reactors. A battery of dispersion and precipitation strengthened (DPS) NiMo-based alloys containing varying amount of SiC (0.5-2.5 wt.%) was prepared via a mechanical alloying (MA) route followed by spark plasma sintering (SPS), rapid cooling, high-temperature annealing and water quenching. Lab X-ray Diffraction (XRD), Electron Back Scattering Diffraction (EBSD), and Transmission Electron Microscopy (TEM) were employed in the microstructural characterization of this newtype of alloys. It is shown that the NiMo matrix of these alloys is effectively reinforced by dispersion of SiC from the initial powder mixture and nano-Ni3Si precipitates, which precipitated during the sintering/annealing process. Furthermore, the matrix is strengthened by solid-solution of Mo in Ni. As a result, these newly developed NiMo alloys take advantage of dispersion, precipitation and solid solution strengthening, which leads to their superior mechanical properties. (C) 2016 Elsevier Ltd. All rights reserved.