Effect of alloying elements on the microstructure and high-temperature oxidation behavior of yttrium-based alloys

作者：Xijie Wu, Ao Liu, Zixie Wang, Jie Pan, Yuming Liu, Jun Li, Hui Li, Qiliang Mei, Jing Gao, Mengqi Wang, Xueshan Xiao · 发表于：Materials Chemistry and Physics · 年份：2025 · DOI：10.1016/j.matchemphys.2025.130884 · 被引用次数：4 · 研究领域：High-Temperature Coating Behaviors、Intermetallics and Advanced Alloy Properties、Nuclear Materials and Properties

Yttrium hydride is recognized as an effective neutron moderator material due to its superior thermal stability and high hydrogen retention capability at elevated temperatures. In this study, the influences of alloying elements Zr, B, and Dy on the microstructure, microhardness , and high-temperature oxidation resistance of yttrium-based alloys were systematically investigated. The primary objective was to mitigate cracking issues encountered during hydrogenation and subsequent operational applications of these alloys. Yttrium-based alloys with varying compositions were fabricated through vacuum arc melting . The microstructure and phase composition of these alloys were characterized. Experimental results revealed that Dy was solid dissolved in the Y matrix for solid solution strengthening, while Zr with limited solubility precipitated as α-Zr for second-phase strengthening, both significantly improving the alloy hardness. Simultaneously, grain refinement is achieved through the formation of YB 2 and ZrB 2 compounds by the B element, leading to further optimization of mechanical properties. High-temperature oxidation experiments conducted at 900 °C revealed that optimal oxidation resistance was exhibited by B-containing alloys (Y-1.2B and Y-1.2B-5Dy), attributable to the formation of highly stable borides at grain boundaries. In contrast, antioxidant performance was found to be degraded due to grain boundary corrosion exacerbated by preferential oxidation of Zr elements. The f...