| Summary: | 碩士 === 國立勤益技術學院 === 化工與材料工程系 === 93 === The nano- Ni-Al2O3 composite coating can be used in special working situation of MEMS. However, the Al2O3 particles aggregate in the Ni-Al2O3 composite coating easily. The welled-dispersion of particles is more important to obtain a fine electrodepositing composite coating. It could enhance the amounts of Al2O3 particles in the deposited layer which reducing the concentration of electrolyte to assist the dispersion of particles. Finally, the hardness of composite coating is elevated by adding the Al2O3 nano-particles into the bath under the concentration of diluted nickel bath. The obtained value of hardness is 415 Hv excellently and the amount of amounts of Al2O3 particles in the deposited layer is 26.87 Vol% when electrodeposition was carried out with a generic bath which was consisted of nickel sulfate hexahydrate of 1.27 M containing nano-particles of 20 g/L. However, the hardness of composite coating is reduced when the nickel base is diluted. Thus, the analysis of morphologies and textures of deposited layer was observed by SEM, FE-SEM, AFM and XRD in this research. Otherwise, the influence of experimental parameters is discussed by the Voltammetry method. Finally, the composite coating is done on the aspect ratio 4 of electroforming. Furthermore, the preparation of composite coating is considered on the cylindrical reactor by the fluidized bed. The result is discussed the interaction between the operational parameters with the aspect ratio in the LIGA micro-structure system.
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