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The process parameters that influence the performance of nano-size hydroxyapatite powder such as purity, granularity, and crystallinity include the mass ratio between Ca(N03)2·4H20 and (NH4)2HP04, the PH value of reaction liquid, the temperature of sintering and the time of heat preservation. Orthogonal experiments with different process parameters are designed; experiments were carried out with every process parameter take 4 different values. Membership function of four process parameters factors were established, and influence fuzzy relation matrix of them to the quality of nano-size hydroxyapatite powder was determined. The result of experiment planed in advance can be predicted using fuzzy evaluation which can enhance the quality of the nano-size hydroxyapatite powder.

The traditional mechanical plating method is not suitable for parts of big bulk and of complex surface. In order to overcome above shortcoming of mechanical plating, a novel wet ultrasonic mechanical plating process was present by integrating the theories of mechanical plating and ultrasonic shot peening. Wet ultrasonic mechanical plating equipment which includes the ultrasonic generator, ultrasonic transducer and amplitude transformer horn was designed. Galvanized tests were carried out using the equipment. The properties of the plating layer were tested. The results show that plating layer whose maximum thickness can reach 30 μm can be gotten on the surface of workpiece. The bonding strength between the coating and substrate is satisfactory.