ELECTROLYSIS EXPANSION PERFORMANCE OF MODIFIED PITCH BASED TiB_2?C COMPOSITE CATHODE IN K_3AlF_6/Na_3AlF_6?AlF_3?Al_2O_3 MELTS

摘要

Electrolysis expansion of pitch, modified by furan, phenolicaldehydernand epoxy, based TiB_2-C composite cathodes inrn[K_3AlF_6/Na_3AlF_6]?AlF_3?Al_2O_3 melts were investigated, andrnTGA was used to study dynamics of pyrolytic process aboutrnvarious modified pitch. The results show that, compared withrnelectrolysis expansion of unmodified pitch based compositerncathode, pitch modified by furan, phenolic-aldehyde and epoxyrnbased composite cathodes all exhibit lower electrolysis expansionrnwhich are 1.61 %, 1.62 % and 1.68 % respectively. The maximumrndepressed amplitude can reach 13.77 %. Apparent activationrnenergy (AAE) concerning pyrolysis process of pitch is related tornelectrolysis expansion of composite cathodes. The higher thernAAE, the lower the electrolysis expansion, and the AAE ofrnunmodified pitch is 47.21 Kj/mol, while the AAE of pitchrnmodified by furan, phenolic-aldehyde, and epoxy are 66.25rnKj/mol, 57.07 Kj/mol and 63.24 Kj/mol severally. The values ofrnthem can account for test result of electrolysis expansionrnmentioned above.