Fuzzy evaluation of process parameters when synthesizing nano-size hydroxyapatite using solgel method

The process parameters that influence the performance of nano-size hydroxyapatite powder such as purity, granularity, and crystallinity include the mass ratio between Ca(NO
₃
)
₂
-4H
₂
O and (NH
₄
)
₂
HPO
₄
, 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.