Comparative analysis of modern methods of production of Al – Zr ligatures

A brief overview of modern industrial and experimental methods for the synthesis of aluminozirconium ligatures is performed. The basic regularities of the proceeding processes, and also properties of the obtained ligatures are considered, technical and economic indicators and prospects of development of the considered technologies are estimated. The comparative estimation of key parameters of the most promising technologies for industrial application is carried out, the influence of temperature, a mode of synthesis and a kind of initial raw materials on profitability of the process is estimated. Aluminothermic and electrolytic methods of ligature synthesis are considered in more detail, the views of other authors on the kinetics of ongoing processes are taken into account, and an overview of the influence of electrolyte composition and electrolysis mode on the structure and properties of produced alloys is presented. It has been shown that, depending on the method, in a wide temperature range (80 – 1000 oC), Al – Zr master alloy with a zirconium content up to 57 wt.% can be obtained. However, all existing methods for the production of Al – Zr master alloys have significant drawbacks, which lead to the relatively high cost of the master alloys, the presence of hazard waste and low production efficiency. It is concluded that along with the current methods of direct fusion of metals and aluminothermic synthesis, it is promising to obtain ligatures by electrolysis of oxide-fluoride melts KF – NaF – AlF3 using zirconium oxide as the main metalcontaining raw material. The results of experimental testing of a new method for obtaining Al – Zr master alloys via electrolysis of oxide-fluoride melts are presented. It has been established that the developed technology makes it possible to maximize the extraction of zirconium from the oxide, to continuously obtain master alloys with a high zirconium content, excluding the accumulation of unclaimed waste. The study was performed with the financial support of the Russian Foundation for Basic Research within the research project No. 19-33-90144.

Effects of zirconium addition on electrochemical and mechanical properties of Mg-3Zn-1Ca-1RE alloy

Purpose The effect of zirconium, zinc, calcium and rare earth group as the alloying elements on mechanical properties and corrosion behavior of magnesium alloys was investigated in the simulated body fluid. Design/methodology/approach Pure magnesium and the alloying elements were melted and zirconium was finally added to obtain different alloys. The castings were annealed and some samples were aged heat treated. X-ray fluorescence was used for the elemental analysis and LSV was used for electrochemical corrosion evaluations. Findings Results showed that corrosion resistance decreases with increasing zirconium content. The lowest corrosion rate was obtained for the samples containing 0.3% and 0.45% of Zr from annealed and aging heat-treated samples, respectively. Yield stress enhances with increasing the zirconium content and degrades by the aging heat treatment. Originality/value These alloys were studied for the first time. Effect of casting without using protective flux and vacuum furnaces. Effect of annealing at 440°C for 2 h and artificial aging at 200°C for 16 h. Alloy’s electrochemical behavior on the body’s simulation environment has been investigated. Improvement of mechanical properties after annealing heat treatment by high zirconium percentage.