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The coating was obtained by electroless plating Ni-P nano Al2O3 on AZ91D magnesium alloys under ultrasound wave. The metallographic microscope and micro sclerometer were used to characterize the structures and hardness of coating. The results showed that in the optimal conditions, ultrasonic electroless plating can increase the coating hardness value by 170HV and extend the coating corrosion resistance time by 130s; inorder to reach the same corrosion resistance time or hardness value, the temperature under ultrasonic decreases 20°C than that without ultrasonic wave; ultrasonic wave can improve the deposition rate, refine the grains and inhibit the nano particles to agglomerate.

Fe2B is a kind of typical intermetallic compound, which has good corrosion resistance in molten zinc. However, the fatal intrinsic brittleness limits its further application in the Hot-Dip Galvanizing Industry. Therefore, it is worthwhile to improve the toughness of Fe2B phase. In this study, the fracture toughness property of Fe2B phase with and without micro-addition chromium is investigated. In comparison with pure Fe2B phase, the intrinsic brittleness of Fe2B phase with chromium is lower. In addition, the valence electron structure of Fe2B containing various chromium content is calculated by the method of bond length difference (BLD). The results show that, in the (Fe1-x Crx)2B phase, the number of covalent electron pairs and the weaker bond energy are increased by the substituting atom-Cr. The calculated results are in good agreement with experimental observations.

The Kurdjumow -Sachs mechanism of martensite transformation is investigated in detail in this paper. The distortion matrixes of the first shear, the second shear and lineal adjustment according to the K-S mechanism are calculated. From the lattice distortion matrix, we can obtain invariant normal planes. According to the assumption that the habit plane is constructed with some of the invariant normal planes, the macroscopic habit plane (225)A is also discussed. The results show that the K-S mechanism can account for the relief effects, habit plane, orientation relationship and the change of structure.

A spectral absorption of the ferrous ion in fluxing was investigated in this paper due to the significant effect of ferrous ion on the quality of hot-dip galvanizing production. Based on analysis of spectrophotometry, an automatic detection equipment of ferrous ions is developed according to its special characteristics. On-line measuring of ferrous ion in fluxing of the hot-dip galvanizing is realized by the micro-pump and the equipment. Results show that the lowest limit to be detected is 0.1 g/L, measuring errors are less than 0.05 g/L, the linear equations of the absorption and concentration of the ferrous ions shows a good correlation coefficient which is 0.99995 when the ferrous ions concentration is between 0.1g/L and 10g/L in fluxing.