Magnetic composite fluid optimization for KDP crystal polishing based on a D-optimal mixture design.

Abstract

The potassium dihydrogen phosphate (KDP) crystal is a kind of electro-optical nonlinear optical crystal with excellent performance, and has attracted much attention from researchers due to its wide application prospects. Some KDP processing techniques have been developed, but polishing KDP with a magnetic composite fluid (MCF) has not been reported, to our knowledge. Accordingly, first, taking the water solubility of KDP into account, a non-water-based MCF is developed based on previous research. Then, orthogonal experiments are used to determine optimal processing parameters of MCF. Finally, a D-optimal mixture design is used to establish a mathematical model of the influence of each component factor on surface roughness, and the ratio of key components in MCF is optimized. The results show that the theoretical optimum ratio is 20wt.% base liquid (lauryl alcohol and Triton X-100), 39.962wt.% carbonyl iron particles, and 25.038wt.% F e 3 O 4. The KDP surface roughness (Ra) after 60min of polishing converges to 7.5nm, consistent with expected estimates, indicating that the formulation optimized by this method is effective and reliable.