The Gd-Co-Mn alloys with compositions of Gd33.3Co66.7,Gd33.3Mn66.7,Gd22.2Co74.8Mn3 and Gd25Co70Mn5 were prepared and examined by X-ray diffractometer.The electrochemical properties of these alloys such as discharge capacity,cycling performance and high rate dischargeability were investigated by battery testing instruments in alkaline electrolyte.The discharge capacity of Gd22.2Co74.8Mn3 was the highest among these alloys at the same discharge current density,and the maximum value was 376.7 mAh/g discharged at 150 mA/g.The discharge capacities of the alloys Gd33.3Co66.7 and Gd33.3Mn66.7 reached their maxima(about 225 and 325 mAh/g)at discharge current density of 150 mA/g.A comparison of the electrochemical performance of the Gd-Co-Mn alloys revealed that the alloy Gd22.2Co74.8Mn3 possessed better electrochemical performance and had better discharge capacity,cycle stability,while the alloy Gd25Co70Mn5 had a better high rate discharge ability.In general,the electrochemical performance of ternary alloys was better than binary alloys in this case.
Phase diagram is an important basis for materials research and materials application.The phase relations of the Nd-Zr-Si ternary system at 773 K were investigated by X-ray powder diffraction analysis,metallographic analysis and scanning electron microscopy with en-ergy dispersive analysis.The isothermal section of the phase diagram of the Nd-Zr-Si ternary system at 773 K was determined.The isother-mal section of the system consisted of 13 single-phase regions,23 two-phase regions and 11 three-phase regions.The homogeneity range of α-NdSix was from 63 at.% to 66 at.% Si(with x=1.70-1.94).The maximum solid solubilities of Nd in Zr-Si binary compounds and Zr in the Nd-Si binary compounds were observed less than 1 at.% at 773 K.
The isothermal section of the phase diagram of the Dy-Zr-Si ternary system at 773 K was determined by X-ray diffraction (XRD) analysis, metallographic analysis, and scanning electron microscopy (SEM) with energy-dispersive spectrometer (EDS) analysis. The isothermal section consists of 13 single-phase regions, 23 two-phase regions, and 11 three-phase regions. The solubilities of Zr in Dy, Dy5Si4, Dy5Si3, DySi, DySi2, DySi1.67, and Dy in Zr, Zr2Si, Zr3Si2, Zr5Si4, ZrSi, and ZrSi2 were determined at 773 K.
