Zr-Al-Ni-Cu-Co alloys

Figure 4.81 shows a comparison between the measured of Zr-Al-Ni-Cu-Co amorphous alloy and the calculated H" ( HJ. The results agree well. Since the temperature coefficient of the C" function is very large, does not increase as T, increases. 

These different interrelated structures, with special attention to their occurrence in Al-X-Y ternary alloys (X = Ti, Zr, Hf, V, Nb, Ta, Mo Y = V, Cr, Mn, Fe, Co, Ni, Cu, Zn) have been considered by Kumar (1990). According to differences in chemical bonding, mechanical and physical properties, Kumar considered (for various stoichiometries) three main groups of structures ... 

Similarly, a number of amorphous alloys based on Fe-Zr, Ni-Zr, Co-Zr, Ni-Nb, have not shown any increase in activity over that expected for the mechanical mixture of the crystalline components [571]. For Ni-Nb the overpotential has even increased. Only Cu-Ti alloys have shown apparent synergetic effects, but the results of Machida et al. [89] (cf. Fig. 32) should also be taken into account. Jorge et al. [152] have observed higher activity for the amorphous form of Cu-Ti alloys, but they have attributed it to the preferential dissolution of Ti in the amorphous sample under cathodic load, with formation of a relatively porous Cu layer. The same effect was obtained more rapidly by means of HF etching [89,152]. 

Some alloys may be more easily obtained by electrodeposition than by metallurgical processes. This is particularly tme for alloys composed of metals having large differences in melting temperatures or metals that cannot be mixed in a liquid state. Such metals can very often be codeposited from the solutions (e.g., alloys Ag-Ni, Ag-Co, and Cd-Co). Taking into account that some metals cannot be electrodeposited from the aqueous solutions (Ti, V, W, Nb, Zr, etc.), they could be electrodeposited from the melts of their salts. In recent times, the processes of metal and alloy electrodeposition from the room-temperature molten salts were also investigated and developed (cf. electrodeposition of Al-Cu, Al-Co, Al-Ni alloys from AlCls-MeEtlmCl melt). 

Experiments by [1999Fuj] on the deoxidation equihbrium for aluminum in liquid iron and an Fe-36%Ni alloy under pressure controlled by H2/H2O gas at 1700°C resulted in the interaction parameters between Al and O in hquid iron and the Fe-36%Ni alloy. [1990Kuz] studied the effect of alloying with Zr, Al-Zr, Hf and Al-Hf on oxygen activity in Co-Cu-Fe-Ni alloys at 1600°C. 

A mercury cathode finds widespread application for separations by constant current electrolysis. The most important use is the separation of the alkali and alkaline-earth metals, Al, Be, Mg, Ta, V, Zr, W, U, and the lanthanides from such elements as Fe, Cr, Ni, Co, Zn, Mo, Cd, Cu, Sn, Bi, Ag, Ge, Pd, Pt, Au, Rh, Ir, and Tl, which can, under suitable conditions, be deposited on a mercury cathode. The method is therefore of particular value for the determination of Al, etc., in steels and alloys it is also applied in the separation of iron from such elements as titanium, vanadium, and uranium. In an uncontrolled constant-current electrolysis in an acid medium the cathode potential is limited by the potential at which hydrogen ion is reduced the overpotential of hydrogen on mercury is high (about 0.8 volt), and consequently more metals are deposited from an acid solution at a mercury cathode than with a platinum cathode.10... 

Rotating Electrode Atomization (REP, PREP) -20 Standard deviation 1.3-1.5 Armco Fe, Cu, Al, Zn, Co-Cr, Ti, Zr, Ni alloys. Low carbon steels SlO2 1-10 -0.04 Spherical, very smooth, ultraclcan particles, Relatively high EE High cost, Low capacity and volume, D Relatively Coarse particles I... 

Thirty-five nonradioactive elements were also determined by ICPMS and ICP-OES. Of these, titanium was the most abundant as it is used for alloying (0.75% as mentioned earlier), and some amounts of Al, Ca, Co, Cu, Ni, Pb, Si, Zn, and Zr, as seen in Table 2.8 (Trueman et al. 2004). Some of these traces were also found in DU fragments recovered from Kosovo (Pollanen et al. 2003). 

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