The aim of this work was to improve the properties of Ni-P coating on SiCp/Al composites. The effect of rare earths addition on Ni-P coating structure was investigated by means of scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffractometer (XRD) and electrochemistry methods. The results showed that as Y or La concentration was 0.15 g/L in plating solution, the highest value of deposition rate of Ni-P coating was found. And the structure of the obtained coating was modified to part of crystalline state from single amorphous Ni, such as Ni3Y or Ni3La, Ni5Y or Ni5La, Ni2P2Y or Ni2P2La. The properties of the Ni-P-RE alloy coating were improved greatly, for example, crystalline size became fine and compact, the free corrosion potential of the coating enhanced remarkably. Y had a better effect on the properties of the coating compared with La.
The Li1.02NbxMn2-xO4 (x=0,0.005,0.01,0.02,0.04 and 0.1) materials were prepared by solid-state reaction method in which Li2CO3 , electrolytic MnO2 and Nb2O5 were used as reactants. The influences of the Nb5+ doping on structure, morphology and electrochemical performance were systemically investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV) and AC impedance. XRD test showed that the prepared samples had single spinel structure although there was impurity phase of LiNbO3 existing in Li1.02NbxMn2-xO4 phase after Nb5+ doping. The doped materials with Nb5+ had smaller lattice parameters and crystal volume compared with pristine Li1.02Mn2O4. The endurance of overcharge was largely improved. In addition, the small amount of Nb5+ doping could increase the material conductivity.
