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用快淬技术制备了Mg_2Ni_(1-x)Cu_x(x=0,0.1,0.2,0.3,0.4)合金,用XRD、SEM、HRTEM分析了铸态和快淬态合金的微观结构,测试了合金的气态贮氢动力学性能和电化学贮氧动力学。结果表明,所有快淬态合金均具有纳米晶结构,没有非晶相。Cu替代Ni不改变合金的主相Mg2Ni,而是使合金的晶粒显著细化。Cu替代Ni和快淬处理均显著地提高了合金的气态及电化学贮氢动力学性能。当淬速从0 m/s(铸态被定义为淬速0 m/s)提高到30 m/s时,Mg_2Ni_(0.8)Cu_(0.2)合金的5 min吸氢饱和率从56.7%增加到92.7%.20 min放氢率从14.9%增加到40.4%,高倍率放电能力从38.5%增加到75.5%,氢扩散系数从8.34×10~(-12)cm~2/s增加到3.74×10~(-11)cm~2/s。
The microstructure of Mg_2Ni_ (1-x) Cu_x (x = 0,0.1,0.2,0.3,0.4) alloys was prepared by rapid quenching technique. The microstructures of as-cast and quenched alloys were characterized by XRD, SEM and HRTEM. The kinetic properties of hydrogen storage and electrochemical oxygen storage kinetics. The results show that all the quenched alloys have nanocrystalline structure and no amorphous phase. The substitution of Cu for Ni does not change the main phase Mg2Ni of the alloy, but the grain of the alloy is significantly refined. Cu substitution Ni and quenching treatment significantly improve the kinetics of the gas and electrochemical hydrogen storage alloys. When the quenching speed increased from 0 m / s (the as-cast state was defined as quenching rate of 0 m / s) to 30 m / s, the 5 min hydrogen saturation of Mg_2Ni_ (0.8) Cu 0.2 alloy increased from 56.7% 92.7%, the hydrogen release rate increased from 14.9% to 40.4% at 20 min, the high rate discharge capacity increased from 38.5% to 75.5%, and the hydrogen diffusion coefficient increased from 8.34 × 10 ~ (-12) cm ~ 2 / s to 3.74 × 10 ~ (-11) cm ~ 2 / s.