Mg₂Ni_0.9Co_0.1合金微观组织与储氢性能研究

The Mg₂Ni_{0. 9}Co_{0. 1} hydrogen storage alloy was prepared by metallurgical method, and the phase composition and microstructure of the alloy were invesiagted by XRD and SEM/EDS, meanwhile the hydrogen absorption and desorption properties of the alloy were anlyzed by PCT and DSC. The results reveal that the as-cast alloy is composed of peritectic Mg₂Ni phase, Mg-Mg₂Ni eutectic structure and a small amount of the first precipitated Mg-Ni-Co ternary phase. The element Co can be dissolved in the Mg₂Ni phase to form a Mg₂(Ni, Co)solid solution phase. The alloy is transformed into Mg₂NiH₄ phase, Mg₂Ni_{0. 9}Co_{0. 1}H₄ phase and MgH₂ phase after hydrogen absorption. The partial substitution of Co for Ni in the Mg₂Ni significantly improves the isothermal de-/hydrogenationkinetic properties of the alloy, and the hydrogen release temperature of Mg₂Ni_{0. 9}Co_{0. 1} hydride is significantly reduced. The initial hydrogen release temperature is about 200 ℃.