This work studied the microstructure, mechanical properties and damping properties of MgNiY and MgZnNiY alloys systematically. The difference in the evolution of the long-period stacked ordered (LPSO) phase in the two alloys during heat treatment was the focus. The morphology of the as-cast MgNiY presented a disordered network. After heat treatment at 773 K for 2 hours, the eutectic phase was integrated into the matrix, and the LPSO phase maintained the 18R structure. As Zn partially replaced Ni, the crystal grains became rounded in the cast alloy, and lamellar LPSO phases and more solid solution atoms were contained in the matrix after heat treatment of the MgZnNiY alloy. Both Zn and the heat treatment had a significant effect on damping. Obvious dislocation internal friction peaks and grain boundary internal friction peaks were found after temperature-dependent damping of the MgNiY and MgZnNiY alloys. After heat treatment, the dislocation peak was significantly increased, especially in the alloy MgNiY. The annealed MgNiY alloy with a rod-shaped LPSO phase exhibited a good damping performance of 0.14 at ε=10, which was due to the difference between the second phase and solid solution atom content. These factors also affected the dynamic modulus of the alloy. The results of this study will help in further development of high-damping magnesium alloys.

中文翻译：

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LPSO相主导的Mg-Ni-Y和Mg-Zn-Ni-Y合金的显微组织和阻尼性能

系统研究了MgNiY和MgZnNiY合金的显微组织、力学性能和阻尼性能。两种合金在热处理过程中长周期堆叠有序（LPSO）相演变的差异是焦点。铸态MgNiY的形貌呈现无序的网络状。在773 K热处理2小时后，共晶相融入基体中，LPSO相保持18R结构。由于Zn部分取代了Ni，铸造合金中的晶粒变圆，MgZnNiY合金热处理后基体中含有层状LPSO相和更多的固溶体原子。 Zn 和热处理对阻尼都有显着影响。 MgNiY和MgZnNiY合金的温度相关阻尼后发现明显的位错内耗峰和晶界内耗峰。热处理后，位错峰显着增加，特别是在合金MgNiY中。具有棒状LPSO相的退火MgNiY合金在ε=10时表现出0.14的良好阻尼性能，这是由于第二相和固溶体原子含量之间的差异。这些因素也影响了合金的动态模量。这项研究结果将有助于高阻尼镁合金的进一步开发。