The Ni-P-W/nano-Al2O3composite coatings were deposited on the surface of sintered NdFeB permanent magnet by electroless plating method. The morphology and the phases of Ni-P-W/nano-Al2O3composite coatings were investigated using scanning electron microscopy and X-ray diffraction respectively. The hardness and the corrosion resistance of the composite coatings were also tested. The results indicated that the composite coatings morphology appears closely nodules morphology, and the microhardness increases with increasing incorporation of Al2O3ratio. Compared with NdFeB magnet and Ni-P-W alloy coatings, the corrosion resistance of the composite coatings was superior to that of the NdFeB magnet and the alloy coating obviously.

The Ni-P-W/Al2O3composite coatings were deposited on the surface of sintered NdFeB permanent magnet by electroless plating method. The morphology and the phases of Ni-P-W/Al2O3composite coatings were investigated using scanning electron microscopy and X-ray diffraction respectively. The hardness and the corrosion resistance of the composite coatings were also tested. The results indicated that the composite coatings morphology appears closely nodules morphology, and the microhardness increases linearly with increasing incorporation of Al2O3ratio. Compared with NdFeB magnet and Ni-P-W amorphous alloy coating, the corrosion resistance of the composite coatings was superior to that of the NdFeB magnet and the amorphous alloy coating obviously. However, for the corrosion resistance of Ni-P-W/Al2O3composite coatings with different Al2O3concentration, there is not a linear increase with the Al2O3concentration increasing. The self-corrosion potential of Ni-P-W/Al2O3composite coatings reaches the highest value while increasing incorporation of Al2O3ratio up to 10 g/L.

This paper adopted freeze casting method to prepare porous Al2O3ceramic bodies with interconnected pore channels as a preform. The preform was pressureless infiltrated with Nb-Al binary alloy by using electromagnetic induction furnace. The results indicated that the Nb-Al melt solidified as a sphere-like body under the surface tension driving. It was difficult to obtain Nb-Al binary alloy matrix Al2O3ceramic composites. However, the wettability between Nb-Al melt and porous Al2O3ceramic bodies was improved obviously while the Ti and Cr alloying elements were added into Nb-Al binary alloy. Also, the resultant Nb-35Ti-20Al-10Cr melt was filled into the interconnected pore channels existed in the Al2O3preform by pressureless infiltration.

The electronic structure and optical properties of wurtzite ZnO nanofilms with different thickness are investigated systematically by using the first-principles approach. The results indicate that the valence band properties of the ZnO nanofilms are mainly determined by the Zn: 3d state and O: 2p state. And its conduction band properties are determined by Zn: 4s state and Zn: 4p state. The band gap decreases with the thickness of nanofilms increasing in [0001] direction. It is also found that the interband transition absorption edge of ZnO nanofilms decreasing from 5.5 eV to 2.7 eV with the thickness of nanofilms increasing from single layer to five layers. The interband transition of reflection spectrum occurs mainly in the range of 10 eV to 18 eV, which is in line with the ionic bonding characteristic of wurtzite ZnO.

¹̄The Ni-P-W/Al2O3 composite coatings were deposited on the NdFeB magnetic materials surface by electroless plating method. The morphology of Ni-P-W/Al2O3 coatings was investigated using scanning electron microscopy. And the X-ray diffraction was used to identify the phase constituents. The interfacial bonding strength between Ni-P-W/Al2O3 composite coatings and NdFeB matrix was also tested. The results indicated that the interfacial bonding strength is prone to be increased while the Al2O3 powders co-deposited with Ni-P-W coatings. And the interfacial bonding strength would reach the highest value when the Al2O3 concentration is in rang of 5gL-1 to 10gL-1.