本研究使用 Mg-5Y (wt%) 合金作為基材並進行內部氫化處理。以 275 ℃、300 ℃ 及 325 ℃ 為處理溫度、36 小時和 48 小時為吸氫時間，於 0.34 MPa 氫氣壓力下進行內部氫化後在真空下放氫 1 小時，並分析試片之成分、微觀結構及機械性質以探討內部氫化作用對 Mg-5Y 合金之影響。
研究結果顯示 Mg-5Y 合金經內部氫化作用後可得均勻散佈於 Mg 基底的 YH2 氫化物。隨著內部氫化處理溫度從 275 ℃ 提升至 325 ℃，YH2 含量增加且均勻散佈，但伴隨著基底中 Y 元素損耗，使 Mg-5Y 合金於內部氫化作用後造成固溶強化效果下降，導致材料硬度及強度下降。隨著內部氫化處理時間從 36 小時增加至 48 小時，Mg-5Y 合金晶粒成長更為明顯，材料內部總晶界面積減小而無法阻礙差排滑移，導致材料硬度及強度下降。
本研究中最佳參數為 300 ℃ 內部氫化處理 36 小時，因其無晶粒成長且形成之氫化物含量少，保持試片原固溶強化效果，使其硬度及強度無下降趨勢。

In this study, internal hydrogenation was performed on Mg-5Y (wt.%) alloy. The hydrogenation was carried out at 275, 300, and 325 ℃ under 0.34 MPa of hydrogen for 36 and 48 hours, and followed by dehydrogenation for 1 hour. The effects of internal hydrogenation on composition, microstructure and mechanical properties of Mg-5Y alloy were studied.
The results show that uniformly-distributed YH2 on the Mg matrix can be obtained after internal hydrogenation of Mg-5Y alloy. As the temperature increases from 275 ℃ to 325 ℃, the amount of YH2 increases and YH2 distributes more uniformly. However, with the loss of Y element in the matrix, the effect of solid solution strengthening after internal hydrogenation is reduced, resulting in decrease of hardness and the strength. The grain growth of Mg is observed clearly when the hydrogenation time increases from 36 to 48 hours. The total grain boundary area inside the material is reduced and its ability to hinder the dislocation slip decreases, resulting in the decrease in hardness and strength of the material.
The optimal treatment temperature and time in this study are 300 ℃ and 36 hours, respectively. Mg-5Y alloy prepared with these parameters has no grain growth and lower hydride content. The solid solution strengthening effect is maintained, and its hardness and strength do not decrease.

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