Advanced technology for Al-Zr alloy synthesis: Electrochemical investigation of suitable low-melting electrolytes

Aluminium-zirconium alloys start to be attractive in various fields such as military, aerospace industry, nuclear reactions or atomic energy. The investigation of low-temperature sodium and potassium cryolite based melts with the different additions of ZrO2 was realized in order to develop the scientific basis of the technology for aluminium-zirconium alloy synthesis. The electrical conductivity of NaF-AlF3-ZrO2 and KF-AlF3-ZrO2 systems as a function of temperature was studied by a tube-type cell with fixed distance between the electrodes, applying ac-techniques with a sine wave signal with small amplitude in the high frequency range. The addition of the aluminium fluoride varied in the range (33–38) mol % in sodium cryolite melts (molar ratio MR = n(Na(K)F)/n(AlF3) = 2.0–1.6) and from 40 mol % to 45.5 mol % (MR = 1.5–1.2) in the potassium cryolite system. Zirconia was added into the basic two-component melts in amounts of (1–4) wt % for sodium system and (1.7–5.2) wt % for potassium system. All measured data were evaluated by the regression analysis (the least square method) for calculation of the electrical conductivities in both investigated melts. [Display omitted] •The new progressive methods of Al-Zr alloys preparation were investigated.•Low-melting electrolytes are suitable for electrochemical production of alloys.•Electrical conductivity of NaF(KF)-AlF3-ZrO2 systems was measured.•Different compounds and ions created during electrochemical reaction were defined.•All data were evaluated by regression equations describing electrical conductivity.