The Ni-P/TiO2 composite film on sintered NdFeB permanent magnet was investigated by X-ray diffraction （XRD）,environmental scanning electron microscopy （ESEM）,and energy dispersive X-ray spectrometer （EDX）. The c...The Ni-P/TiO2 composite film on sintered NdFeB permanent magnet was investigated by X-ray diffraction （XRD）,environmental scanning electron microscopy （ESEM）,and energy dispersive X-ray spectrometer （EDX）. The corrosion resistance of Ni-P/TiO2 film coated on NdFeB magnet,in 0.5 mol/L NaCl solution,was studied by potentiodynamic polarization,salt spray test and electrochemical impedance spectroscopy （EIS） techniques. The self-corrosion current density （icorr） and the polarization resistance （Rp） of Ni-P/TiO2 film are 0.22 μA/cm2 （about 14% of that of Ni-P coating）,and 120 kΩ·cm2 （about 2 times of that of Ni-P coating）,respectively. The anti-salt spray time of Ni-P/TiO2 film is about 2.5 times of that of the Ni-P coating. The results indicate that Ni-P/TiO2 film has a better corrosion resistance than Ni-P coating,and the composite film increases the corrosion resistance of NdFeB magnet markedly.展开更多
Effects of process on the deposition rate,corrosion resistance and corrosion potential of Ni-P-nano-TiO2(rutile) electroless composite plating,were studied by using weightless corrosion methods,magnetic thickness gaug...Effects of process on the deposition rate,corrosion resistance and corrosion potential of Ni-P-nano-TiO2(rutile) electroless composite plating,were studied by using weightless corrosion methods,magnetic thickness gauge and electrochemical methods.The results indicated that the optimum formula and process,composed of NiSO4(10g/400mL),NaH2PO2(10g/400mL),NaAc(6g/400mL),H3BO3(6g/400mL),1h,pH=5.5,80℃,100r/min and nano-TiO2 particle(rutile)(4g/400mL),were obtained.Then,it was shown that corrosion resistance of electroless composite coatings Ni-P-nano-TiO2 (rutile) increased 3-4 times,compared with that of electroless coatings Ni-Pin alkaline and salt corrosion media.However,in acid media,corrosion resistance of Ni-P coating was better.展开更多
基金Sponsored by Hi-Tech Research and Development Program of China (2003AA305120)
文摘The Ni-P/TiO2 composite film on sintered NdFeB permanent magnet was investigated by X-ray diffraction （XRD）,environmental scanning electron microscopy （ESEM）,and energy dispersive X-ray spectrometer （EDX）. The corrosion resistance of Ni-P/TiO2 film coated on NdFeB magnet,in 0.5 mol/L NaCl solution,was studied by potentiodynamic polarization,salt spray test and electrochemical impedance spectroscopy （EIS） techniques. The self-corrosion current density （icorr） and the polarization resistance （Rp） of Ni-P/TiO2 film are 0.22 μA/cm2 （about 14% of that of Ni-P coating）,and 120 kΩ·cm2 （about 2 times of that of Ni-P coating）,respectively. The anti-salt spray time of Ni-P/TiO2 film is about 2.5 times of that of the Ni-P coating. The results indicate that Ni-P/TiO2 film has a better corrosion resistance than Ni-P coating,and the composite film increases the corrosion resistance of NdFeB magnet markedly.
文摘Effects of process on the deposition rate,corrosion resistance and corrosion potential of Ni-P-nano-TiO2(rutile) electroless composite plating,were studied by using weightless corrosion methods,magnetic thickness gauge and electrochemical methods.The results indicated that the optimum formula and process,composed of NiSO4(10g/400mL),NaH2PO2(10g/400mL),NaAc(6g/400mL),H3BO3(6g/400mL),1h,pH=5.5,80℃,100r/min and nano-TiO2 particle(rutile)(4g/400mL),were obtained.Then,it was shown that corrosion resistance of electroless composite coatings Ni-P-nano-TiO2 (rutile) increased 3-4 times,compared with that of electroless coatings Ni-Pin alkaline and salt corrosion media.However,in acid media,corrosion resistance of Ni-P coating was better.
