Studies On The Preparation Of Si And Fe-6.5wt%Si Sheet By Molten Salts

This text studied a cheap molten salts for preparation of silicon, compared with someother ways for preparation of silicon, and concluded that FClNaK-SiO₂ molten salts is cheap,can be used,useful for environment protection and so on.The melting point of this molten salts system is studied indicate that followed theincreasing of SiO₂, the melting point of FClNaK-SiO₂ molten salts, initial stage it increasingand when SiO₂ rise to 5%, get a peak.; then descend and when SiO₂ rise to 7%, get a valley;followed the increasing of SiO₂, the melting point will gradual increasing. So SiO₂ be chose at7%. At same time, silicon can be electrodeposed on silicon steel and molybdenum. Silicon beelectrodeposed in this melts system can get good effect of deposition and cost very low,anduseful for environment protection.The technological parameters of silicon electrodeposition were studied in the FClNaK-SiO₂molten salts. The metallurgical structures of the silicon coating were shown by themetallurgical microscope and scanning electron microscope. The optimum composition andtemperature were determined as follows: the concentration of SiO₂ was 6¹2mol%; and thetemperature was about 700℃,i=60 mA/cm2. A thicker silicon coating about 8¹60μm inthickness was obtained by pulsing current compared with direct current deposition.The conditions of the annealing diffusion and siliconizing were given by preparation ofFe-6.5wt%Si sheet. The Fe-6.5wt%Si sheet were prepared from Fe-3wt%Si sheet byannealing diffusion treatment in 1050℃.