Abstract
The process parameters that influence the performance of nano-size hydroxyapatite powder such as purity, granularity, and crystallinity include the mass ratio between Ca(NO3)2·4H2O and (NH4)2HPO4, 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.