Dong Zhi, Ma Zongqing, Yu Liming, Liu Yongchang
State Key Laboratory of Hydraulic Engineering Simulation and Safety, School of Materials Science and Engineering, Tianjin University, Tianjin, China.
Nat Commun. 2021 Aug 20;12(1):5052. doi: 10.1038/s41467-021-25283-2.
With excellent creep resistance, good high-temperature microstructural stability and good irradiation resistance, oxide dispersion strengthened (ODS) alloys are a class of important alloys that are promising for high-temperature applications. However, plagued by a nerve-wracking fact that the oxide particles tend to aggregate at grain boundary of metal matrix, their improvement effect on the mechanical properties of metal matrix tends to be limited. In this work, we employ a unique in-house synthesized oxide@W core-shell nanopowder as precursor to prepare W-based ODS alloy. After low-temperature sintering and high-energy-rate forging, high-density oxide nanoparticles are dispersed homogeneously within W grains in the prepared alloy, accompanying with the intergranular oxide particles completely disappearing. As a result, our prepared alloy achieves a great enhancement of strength and ductility at room temperature. Our strategy using core-shell powder as precursor to prepare high-performance ODS alloy has potential to be applied to other dispersion-strengthened alloy systems.
氧化物弥散强化（ODS）合金具有优异的抗蠕变性、良好的高温微观结构稳定性和抗辐照性，是一类有望用于高温应用的重要合金。然而，由于氧化物颗粒倾向于在金属基体的晶界处聚集这一令人头疼的问题，它们对金属基体力学性能的改善作用往往受到限制。在这项工作中，我们采用一种独特的内部合成的氧化物@W核壳纳米粉末作为前驱体来制备W基ODS合金。经过低温烧结和高能率锻造后，制备的合金中高密度的氧化物纳米颗粒均匀地分散在W晶粒内，同时晶界处的氧化物颗粒完全消失。结果，我们制备的合金在室温下实现了强度和延展性的大幅提高。我们使用核壳粉末作为前驱体来制备高性能ODS合金的策略有潜力应用于其他弥散强化合金体系。
