Research On Preparation Of Zr-Mn Based Hydrogen Storage Alloys By Electro-deoxidation In Molten Salts

The method of electro-deoxidation, a technique which has a short route, low energy consumption and no environmental influence is used for preparation of Zr-Mn based hydrogen storage alloys in CaCl2-NaCl melt. The phase, micro-morphology of the pellets sintered at900℃,1000℃, and1100℃for4hours was researched. We found that the optimum temperature was1000℃through comparing the XRD patterns of the pellets electrolyzed at900℃for8hours.The pellet sintered at1000℃was electrolyzed at850℃and900℃for8hours to study the effect of the electrolysis temperature. The results indicated that raising temperature was beneficial to the electrolysis. The electrolysis time was extended to15hours at900℃. However, the pellet was not electrolyzed completely because of the compact CaZrO3.The Zr-Mn-Ni alloys were prepared with the mixed MnO2, ZrO2and NiO oxides electrolyzed at900℃for15hours. The phase and crystal structure of ZrMn2were changed with Mn partially substituted by Ni. The major phase of the alloy changed from C14-type to C15-type after Ni doped. Further, the cell parameters and volume of C14and C15decreased with the amount of Ni increasing.The MnO2, ZrO2, NiO and TiO2mixed oxides were electrolyzed to obtain the Zr-Ti-Mn-Ni alloy. The cell parameters and volume decreased after Ti substituting Zr while the major phase transformed from C15-type to C14-type. Ti element was considered to be a C14-stabilized element in ZrMn2alloy.