The effects of NaA1H4, TiF3 and NaA1H4-TiF3 co-additive on dehydriding reaction of Mg（A1H4）2 are systematically investigated. The on- set dehydrogenation temperature of the co-doped Mg（A1H4）2 composites decreased ...The effects of NaA1H4, TiF3 and NaA1H4-TiF3 co-additive on dehydriding reaction of Mg（A1H4）2 are systematically investigated. The on- set dehydrogenation temperature of the co-doped Mg（A1H4）2 composites decreased to 74 ℃, which is about 59 ℃ lower than that of pure Mg（A1H4）2. The dehydrogenation kinetics of NaA1H4-TiF3 co-doped Mg（A1H4）2 sample was also improved, which released about 94% hydrogen within 48 min, but no visible hydrogen was released from pure Mg（A1H4）2 under the same conditions. The activation energy of co-doped Mg（A1H4）2 was 85.6 kJ.mol-t, which was significantly lower than that of additive-free Mg（A1H4）2 sample. The synergetic effects of NaA1H4 and TiF3 on the dehydrogenation performance of Mg（A1H4）2 were confirmed. In addition, a possible catalytic mechanism is discussed, regarding the different roles of NaA1H4 and TiF3 on Mg（A1H4）2.展开更多
The effects of the synergistic addition of Er and Sc on the aging and interfacial segregation behaviors of alloys were systematically studied using transmission electron microscopy(TEM)and high-angle annular dark fiel...The effects of the synergistic addition of Er and Sc on the aging and interfacial segregation behaviors of alloys were systematically studied using transmission electron microscopy(TEM)and high-angle annular dark field(HAADF)imaging.The TEM results show that Al3(Sc,Zr)with a core-shell structure can act as nucleation particles forθ′to promote uniform and fine precipitation.The STEM results show that Er solute atoms were preferentially enriched inside theθ′precipitate during thermal exposure at 225℃for 150 h.However,Sc and Mn solute atoms segregated at theθ′/α-Al matrix interface were observed at 300℃.Due to the early enrichment of Er in theθ′precipitate,the slowly diffusing Sc and Mn were segregated to the interface of theθ′precipitate before the severe coarsening of theθ′precipitate,thus further stabilizing theθ′precipitate at higher temperatures.展开更多
基金supported by the MOST Project(2010CB631303,2012AA051901)NSFC(5117108)+1 种基金111 Project(B12015)MOE(IRT-13R30)
文摘The effects of NaA1H4, TiF3 and NaA1H4-TiF3 co-additive on dehydriding reaction of Mg（A1H4）2 are systematically investigated. The on- set dehydrogenation temperature of the co-doped Mg（A1H4）2 composites decreased to 74 ℃, which is about 59 ℃ lower than that of pure Mg（A1H4）2. The dehydrogenation kinetics of NaA1H4-TiF3 co-doped Mg（A1H4）2 sample was also improved, which released about 94% hydrogen within 48 min, but no visible hydrogen was released from pure Mg（A1H4）2 under the same conditions. The activation energy of co-doped Mg（A1H4）2 was 85.6 kJ.mol-t, which was significantly lower than that of additive-free Mg（A1H4）2 sample. The synergetic effects of NaA1H4 and TiF3 on the dehydrogenation performance of Mg（A1H4）2 were confirmed. In addition, a possible catalytic mechanism is discussed, regarding the different roles of NaA1H4 and TiF3 on Mg（A1H4）2.
基金supported by the National Key Research and Development Program of China(Nos.2021YFB3700902,2021YFB3704204,2021YFB3704205)Innovative Research Group Project of the National Natural Science Foundation of China(No.51621003)+3 种基金Beijing Natural Science Foundation,China(No.2202009)Basic Research Program of Jiangsu Province,China(No.BK20191148)Beijing Lab Project for Modern Transportation Metallic Materials and Processing Technology,ChinaJiangsu Key Laboratory for Clad Materials,China(No.BM2014006)。
文摘The effects of the synergistic addition of Er and Sc on the aging and interfacial segregation behaviors of alloys were systematically studied using transmission electron microscopy(TEM)and high-angle annular dark field(HAADF)imaging.The TEM results show that Al3(Sc,Zr)with a core-shell structure can act as nucleation particles forθ′to promote uniform and fine precipitation.The STEM results show that Er solute atoms were preferentially enriched inside theθ′precipitate during thermal exposure at 225℃for 150 h.However,Sc and Mn solute atoms segregated at theθ′/α-Al matrix interface were observed at 300℃.Due to the early enrichment of Er in theθ′precipitate,the slowly diffusing Sc and Mn were segregated to the interface of theθ′precipitate before the severe coarsening of theθ′precipitate,thus further stabilizing theθ′precipitate at higher temperatures.
