An Electrochemical Method for the Preparation of Al-Mg Master Alloys from MgO

2010 ◽  
Vol 650 ◽  
pp. 260-264 ◽  
Author(s):  
Da Li Cao ◽  
Ji Kun Wang ◽  
Si Chen Guo ◽  
Qin Hong Fang ◽  
Zhong Ning Shi

The electrochemical formation of Al-Mg master alloys were investigated in NaCl-MgF2-MgO melt at 850°C. The results revealed that cell voltage was nearly constant during electrolysis process, Mg content in Al-Mg master alloys increased with increasing of electrolysis time when Mg content was less 7.03mass%, Mg content in Al-Mg master alloys can be up to 7.03mass% for 4h electrolysis. The results of XRD indicated that phase structure of the Al-7.03Mg mass% alloy existed single phase α-Al, MgCl2 and NaMgF3 in electrolyte were observed after electrolysis. And the formation mechanism of Al-Mg master alloy was discussed as well.

Author(s):  
Hui Li ◽  
Lei Jia ◽  
Weigang Cao ◽  
Jinglong Liang ◽  
Le Wang ◽  
...  

AbstractIn order to study the process of Fe3O4 reduction by melt electro-deoxidation. Electrochemical method was used to analyze the reduction mechanism of Fe3O4 in NaCl-CaCl2 melts. The effects of cell voltage and time on the product were discussed through constant cell voltage electrolysis. The results showed: (1) The reduction of solid Fe3O4 to metallic Fe is a two-step process for obtaining electrons. (2) The transformation process (600 min, 0–1.0 V) of the electrolysis products with the increase of the cell voltage is as follows: Fe3O4 → FeO → FeO + Fe → Fe. (3) The intermediate product Ca2Fe2O5 was formed (2.0 V, 10–300 min), which inhibited the deoxygenation process in the early stage of the reaction. When the electrolysis time exceeds 60 min, the main reaction is the reduction of Ca2Fe2O5 to Fe.


Author(s):  
Chen-hua Xu ◽  
Jin-zhi Zhang ◽  
Ruo-jun Cheng ◽  
Rui Chen ◽  
Zhu-guang Luo ◽  
...  

Author(s):  
Wenxue Fan ◽  
Hai Hao

Abstract Grain refinement has a significant influence on the improvement of mechanical properties of magnesium alloys. In this study, a series of Al–Ti–C-xGd (x = 0, 1, 2, 3) master alloys as grain refiners were prepared by self-propagating high-temperature synthesis. The synthesis mechanism of the Al–Ti–C-xGd master alloy was analyzed. The effects of Al–Ti–C-xGd master alloys on the grain refinement and mechanical properties of AZ31 (Mg-3Al-1Zn-0.4Mn) magnesium alloys were investigated. The results show that the microstructure of the Al–Ti–C-xGd alloy contains α-Al, TiAl3, TiC and the core–shell structure TiAl3/Ti2Al20Gd. The refining effect of the prepared Al–Ti–C–Gd master alloy is obviously better than that of Al–Ti–C master alloy. The grain size of AZ31 magnesium alloy was reduced from 323 μm to 72 μm when adding 1 wt.% Al–Ti–C-2Gd master alloy. In the same condition, the ultimate tensile strength and elongation of as-cast alloy were increased from 130 MPa, 7.9% to 207 MPa, 16.6% respectively.


2013 ◽  
Vol 668 ◽  
pp. 865-869
Author(s):  
Wan Wu Ding ◽  
Wen Jun Zhao ◽  
Tian Dong Xia

The influence of different solidified velocities on the structure of pure aluminum during the process of refinement by Al-5Ti-0.6C master alloy was studied and the impact mechanism was discussed. The results show that at the same solidified velocity, with the increase of the amount of Al-5Ti-0.6C master alloy, in the solidified structure of pure aluminum, columnar crystals will gradually decrease, while equiaxed crystals will gradually increase. But in the case when the level of addition is the same, the faster the solidified velocity, the greater the number of equiaxed crystals will be in the ingot microstructure. The formation of equiaxed crystals is the result of the dual role of dissociation of crystal particles and heterogeneous nucleation of “TiC particle---Ti transition zone”.


2013 ◽  
Vol 721 ◽  
pp. 282-286
Author(s):  
Guang Hui Qi

In order to settle environment pollution and provide a high effective and low-cost modifier for refining the primary Si in hypereutectic Al-Si alloys, Al-Fe-P master alloys containing 2.0~5.0% phosphorus have been invented by casting method. The Al-Fe-P master alloys can be conveniently produced and an excellent modification can be obtained by adding 0.3~0.8wt% Al-Fe-P master alloy in Al-Si alloys containing 12%-25% Si at a relatively lower modifying temperature. The number of primary Si increases obviously and the average grain size of primary Si decreases largely, less than 50μm. Furthermore Al-Fe-P master alloys have many advantages, such as low cost, convenient operation technology, no pollution, stable and long-term modification effect, easy storage and etc. Al-Fe-P master alloys have overcome the shortages of current modifier and have a good future for hypereutectic Al-Si alloy modification.


Author(s):  
Adrian Nur ◽  
Jundi Rofi’uddien ◽  
Muhammad Abdul Basir ◽  
Nazriati Nazriati ◽  
Fauziatul Fajaroh

<p>The metal oxide composite is used to the microelectronic circuit, piezoelectric, fuel cell, sensor, catalyst, coating for preventing corrosion, and solar cell. The ZnO/CuO is one of the metal oxide composites. The combination of ZnO and CuO is the potential composite used to the catalyst and the anti-bacterial agent. The method used in this research was the electrochemical method in the acetate acid solution. The acetate acid solution used in this research is cheaper than the succinite acid used in the previous research. The electrochemical method has advantages due the easy to control and cheap. The composite resulted was analyzed by the XRD and the FTIR. The aims of this analysis are to know the crystallite phase, structure, and the functional groups of the particle resulted. The analysis showed that the ZnO-CuO composite can be resulted by the electrochemical method.</p>


2011 ◽  
Vol 675-677 ◽  
pp. 1125-1128 ◽  
Author(s):  
Rui Guo ◽  
Xiu Jing Zhai ◽  
Ting An Zhang

The paper studied the preparation of Al-Sc alloy by molten salt electrolysis. LiF-ScF3-ScCl3 as the electrolyte, Sc2O3 as raw material, liquid Al as cathode and graphite as anode. The process condition of preparating Al-Sc alloy includes the influence of current density, electrolysis time, temperature of electrolysis, Back EMF, content of Sc in alloy and current efficiency.The content of Sc in alloy prepared by this method has reached to the maximum of 3.437%. The components of alloys showed by SEM were uniform, it is applicable for commercial purposes. Preparation of Al-Sc alloys with scandium oxide as raw materials, it not only reduce environment pollution, but also decease the cost of production. It is reported in many documents, preparing aluminum base alloy by the method of molten salt electrolysis[1-3], people could make many alloys such as Al-Ce、Al-La、Al-RE、Al-Ti、Al-Si-Ti in the aluminum cell, also the method to prepare some rare earth alloys such as Al-Sr、Nd-Fe、La-Ni was reported[4,5]. Use the method of electrolysis to produce some aluminum base alloy with high-melting-point , difficult to restore , high-priced element is a good method because it is technological process is brief, economy is rational, the technology is feasible, this viewpoint is broadly approved in the world[6]. It isn’t necessary to use high-priced Sc as raw material in preparing Al-Sc alloy with molten salt electrolysis, it could control the Sc amounts in the alloy through the different current efficiency and electrolysis time, production in this method could be continuous or semi-continuous, so it is easy to be automatic controlled. A new molten salt system is used in this paper, we use molten salt electrolysis to produce Al-Sc alloy, take scandium oxide as raw material, through the study of the effect of the current intensity,electrolysis time and the electrolysis temperature , Back EMF and cell voltage, the final production Al-Sc alloy contains Sc 2~6%.


2007 ◽  
Vol 29-30 ◽  
pp. 111-115 ◽  
Author(s):  
S.A. Kori ◽  
V. Auradi

In the present work binary Al-3Ti and Al-3B master alloys were prepared at different reaction temperatures in an induction furnace by the reaction of halide salts like potassium fluoborate and potassium titanium fluoride with liquid molten Al. The indigenously developed master alloys were used for grain refinement studies of Al-7Si alloy and evaluated for their grain refining ability by CACCA studies. The present results suggest that, the reaction temperature influences the size, size distribution and morphology of the intermetallic (Al3Ti in Al-3Ti, and AlB2/AlB12 in Al-3B) particles present in Al-3Ti and Al-3B master alloys. Grain refinement studies of Al-7Si alloy reveal that, Al-3Ti and Al-3B master alloys prepared at 8000C-60 min. have shown better grain refining efficiency on Al- 7Si alloy when compared to the master alloys prepared at 9000C-60 min and 10000C-60 min respectively. In addition, B-rich Al-3B master alloy shows efficient grain refinement than Ti rich Al- 3Ti master alloy.


2018 ◽  
Vol 192 ◽  
pp. 01043
Author(s):  
Savitri Payakkapol ◽  
Nattapon Chayopitak ◽  
Panya Kunsuwan ◽  
Naoto Ohtake ◽  
Sompong Srimanosaowapak

Induction motors have been widely used in various electrical applications. However, their efficiency are still limited due to losses occurring during operation, especially for smaller ratings. Higher the electrical conductivity of motor rotor by lower its impurity content is one of practical and simple way to improve motor efficiency. The aim of this work is to reduce the impurity content of aluminium rotor by addition of boron in the form of Al-5wt%B master alloy and Na2B4O7-NaCl-KCl flux, and then sedimention of their precipitated particles. The purer melt was then cast as rotors for single-phase induction motors. With the amount of addition of boron in aluminium melt in this work, boron in Al-5wt%B master alloy was more pronounced in removing impurities in aluminium melt than that in Na2B4O7. It was found that the rotors made of aluminium melt with lower impurity contents and hence higher electrical conductivity resulted in more enhancement of motor efficiency.


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