Synthesis of Al-Zr Alloys Via ZrO2 Aluminum-Thermal Reduction in KF-AlF3-Based Melts

Synthesis of Al-Zr Master Alloys via the Electrolysis of KF-NaF-AlF3-ZrO2Melts

“…The standard Gibbs energy values ( G • ) of Reactions 1 and 2 at the temperature of 750 • C are equal to 9.4 and −496.5 kJ/mole, respectively. 32,44 This indicates on the predominant reduction of ZrO 2 with the formation of intermetallic compounds 2. In this case reducing of thermodynamic activity of zirconium and shifting of G • to the area of negative values is provided.…”

“…Preparation of melts.-The melts were prepared from individual KF, NaF, AlF 3 , and ZrO 2 reagents (Chemically Pure Grade, OJSC "Vekton", Russia) via the earlier described procedure. [31][32][33] All prepared mixtures were purified by means of potentiostatic electrolysis for removing residuals (electropositive in relation to the aluminum impurities; 2 hours at the graphite cathode potential of +0.2 V relative to the aluminum electrode potential). 41 Zirconium dioxide was added into the purified melts.…”

“…[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] Molten fluoride mixtures of NaF, KF and AlF 3 seem to be more suitable for Al-Zr master alloys synthesis due to having optimal ZrO 2 and Al 2 O 3 solubility. [29][30][31][32][33][34] Nowadays, only attempts for Al-Zr master alloys producing during the electrolysis of cryolite-alumina melt (NaF-AlF 3 ) with ZrO 2 are known. 35 On the other hand, we have demonstrated the ability to synthesize of Al-Sc alloys with 2 wt% scandium by means z E-mail: suzdaltsev_av@mail.ru of electrolysis of KF-NaF-AlF 3 -Sc 2 O 3 melts in a temperature range of 750-950 • C. [36][37][38][39][40] In the present paper, the fundamental principles of the synthesis of Al-Zr alloys and master alloys during the electrolysis of KF-NaF-AlF 3 -ZrO 2 melts are investigated.…”

Review—Synthesis of Aluminum Master Alloys in Oxide-Fluoride Melts: A Review

“…10. 73 The introduction of ZrO 2 into the melt increases the liquidus temperature of both systems, at the same time for melts with CR = 1.3 this increase is sharper. It follows from the dependences that the solubility of ZrO 2 in KF-AlF 3 melts with CR = 1.3 and 1.5 at the temperature of 800 °C is 1.4 and 1.6 mol%, respectively.…”

“…11). 73,75 Stability of formed zirconium compounds in KF-AlF 3 and KF-NaF-AlF 3 melts with ZrO 2 additives was also investigated by DSC and TG methods in Ref. 73.…”