Electrolytic Synthesis Of Reni_5-xAl_x Alloys In The Molten Salt

FFC Cambridge process which has a short route, low energy consumption and no environmental influence is proposed for preparation of rare earth-based AB5type alloy. At present, in order to improve electrochemical properties of the alloy and reduce raw material costs, plenty of study is related to substitution of rare earth metals and nickel in AB5type alloy by the cheaper metals. In this study, mixed rare earth oxides which easy to separate were used to take place of the traditional La2O3, and use Al2O3partially replace Ni in order to improve properties of alloys and reduce production costs.In this study, RENi5alloys were prepared by direct electrolytic deoxidization NiO and mixed rare earth oxides. The reduction pathway from the mixture oxides were studied by examination of partially reduced samples using XRD, SEM with EDS analysis, which were obtained by interrupting the reduction process after different times. The results indicates that first stage of the reaction involved the rapid reduction of NiO to form Ni, there after mixed rare earth oxides were electrochemically reduced and alloyed with Ni to form RENi5.In this study, RENi5-xAlx(x=0.25,0.5)alloys were prepared by FFC Cambridge process by direct electrolytic deoxidization NiO, mixed rare earth oxides and Al2O3. The effects of substituting Ni with Al on the phase structure and morphology on the alloys were investigated in detail. XRD indicates that the alloys consist of a single phase with a hexagonal CaCu5structure and the bulk phase structure of the alloy is not changed by the partial substitution of Ni for Al. The parameters a, c, and the cell volume(V) increase with increasing contents, the reason of this phenomenon is discussed.