Fe-Ni system

Bos et al. [94] compared the performance of ANNs for modelling the Cr-Ni-Fe system in quantitative XRF spectroscopy with the classical Rasberry-Heinrich model and a previously published method applying the linear learning machine in combination with singular value decomposition. They studied whether ANNs were able to model nonlinear relationships, and also their ability to handle non-ideal and noisy data. They used more than 100 steel samples with large variations in composition to calibrate the model. ANNs were found to be robust and to perform better than the other methods. 

Among rechargeable batteries commercially available today (Table 1), only the lead/acid (Pb-A) and Ni-Fe systems can be considered as potential EV power plants because of the cost and scarcity of materials used in other batteries. The performance of the Pb-A and Ni-Fe systems is, however, inherently limited by their low-energy... 

Among near-term and advanced systems, the longest cycle life is expected for Ni-Fe systems (sintered iron electrodes have been reported to be capable of 3000 deep discharge cycles) a very short lifetime (at most 300 cycles achieved before 20% loss of rated capacity) is characteristic of simple alkaline Ni-Zn cells. Other near-term and advanced systems have demonstrated battery, module, or cell cycle life of 400-1000 cycles. Further improvements and reliable transfer of the cycle life achieved in modules into full batteries depend, in general, on the feasibility and rate of technical and engineering progress, rather than on scientific breakthroughs as is the case of the simple alkaline Ni-Zn system. 

The Ni-Fe system developed by Edison in 1901 was the predominant commercial secondary battery till the early 1920s. Past applications have been to railcar lighting, mine lamps, mine vehicles, lift trucks, etc. 

In the Ni-Fe system at room temperature, the a phase extends from 0 to 7% Ni, then a. Fy mixtures from 7 to 50% Ni, and the y phase from 50 to 100% Ni. y-Phase alloys in the Ni-Fe system, known as Permalloys, exhibit a wide variety of magnetic properties, which may be controlled precisely by means of well-established technologies. Initial permeabilities up to 10 in an extremely wide temperature range, as well as coercive fields between 0.16 and 800 A/m, can be obtained (Chin Wemick, 1980). Induced anisotropy of 65-85% Ni alloys can be drastically varied by field annealing and mechanical deformation (slip-induced anisotropy) an order-disorder transformation occurs for Ni3Fe finally, preferential orientation can be induced in 50%Ni-50%Fe. 

In the binary Ni—Fe system, = 0 at about 76 wt%Ni and kg = 0 at about 81 wt%Ni. Small additions of Cu lower the Ni content for which A,g = 0 while Mo additions increase the Ni content for K = 0. Thus different alloy compositions around 78 wt% Ni are available which have optimal soft magnetic properties. General relations of the effect of alloying elements in Ni—Fe-based alloys on K, kg, and on the permeability have been developed in [3.14,15]. Figure 4.3-11 shows the position of the lines for =0 and A,s = 0 in the dis-... 

Metals properties are determined by their nominal composition and use of additives. Figure 2 shows the phase diagram of the Cr-Ni-Fe system. Reported phases have been evaluated by Yang et al. [7] and their properties are summarized... 

Relative width of region of unreliable reaction (5) was estimated as the ratio of difference between maximum and minimal concentrations to minimal concentration in this region. The test-system containing Co [Fe(CN)g] is the most resistant to uncontrolled factors, the lowest detection limit characterizes a film with Ni,[Fe(CN)J. The possibility of test-films application for quantitative determination of nitroxoline is testified. 

With regard to stress-corrosion cracking in the Ni-Cr-Fe system, including both nickel-base alloys and stainless steels, a vast number of papers has been published. A detailed review of work published before 1969 is available and the authors have since published additional data . 

Fig. 7.77 Thermodynamic stability diagram for the Fe-Ni-Cr system at 1 143 K, assuming metal activities to be unity.-, phase boundaries involving Fe —phase boundaries involving Ni ----, phase boundaries involving Cr. The location of environments 1, 2, 3, and 4 are...

Mukherjee studied the gas phase equilibria and the kinetics of the possible chemical reactions in the pack-chromising of iron by the iodide process. One conclusion was that iodine-etching of the iron preceded chromis-ing also, not unexpectedly, the initial rate of chromising was controlled by transport of chromium iodide. Neiri and Vandenbulcke calculated, for the Al-Ni-Cr-Fe system, the partial pressures of chlorides and mixed chlorides in equilibrium with various alloys and phases, and so developed for pack aluminising a model of gaseous transport, solid-state transport, and equilibria at interfaces. 

Mossbauer et al. [294] studied Ir-Fe and Ir-Ni alloy systems over the whole composition range by means of Ir (73 keV) and Fe nuclear resonance... 

Biomimetic chemistry of nickel was extensively reviewed.1847,1848 Elaborate complexes have been developed in order to model structural and spectroscopic properties as well as the catalytic function of the biological sites. Biomimetic systems for urease are described in Section 6.3.4.12.7, and model systems for [Ni,Fe]-hydrogenases are collected in Section 6.3.4.12.5. 

Thiolate-bridged dinickel complexes and, in particular, heterobimetallic Ni/Fe complexes have attracted much interest as model systems for the hydrogenase enzymes. A review covering this... 

The reactions were carried out at temperatures between 353 and 393 K and CO pressures up to 75 atm reaction times were between 20 h and 10 days. Of vital importance are the catalytically active precipitates of Ni or Ni/Fe with carbonyl, cyano and methylthio ligands as carbon sources. Calcium or magnesium hydroxide were used as buffers to prevent the system from becoming too acidic (Huber and Wachtershauser, 2006). 

An empirical treatment developed by Kolb et al. [81, 82] relating UPD behavior to the difference in work function between the substrate and depositing species has been used to explain anomalous co-deposition behavior observed in Ni-Fe and Ni-Zn alloys [83]. Although the relationship appears to hold for pure underpotential deposition limited to a monolayer, it does not satisfactorily predict bulk alloy behavior. For example, based on work function data alone, one would expect Zn-Al and Sb-Al alloys to be formed by underpotential alloy deposition. Recent reports in the literature, however, indicate that alloying in these systems does not occur [46, 84]. 

Very limited investigations have been conducted with this alloy system. The results obtained to date suggest that A1 co-deposits with Fe from solutions of Fe(II) in both AlCl3-EtMeImCl at 25 °C [46] and AlCl3-NaCl at 160 °C [100]. In both studies, the A1 co-deposition process was found to commence at nearly the same potential as the Fe(II) reduction reaction therefore, it was difficult to observe a well-defined voltammetric limiting current for the latter process, regardless of the technique that was employed. This behavior is nearly identical to that seen in the Ni-Al system [47], However, a comparison of the voltammetric results recorded for some of the other... 

The Co system is more reactive as well as much more selective than the Ni and Rh catalyst systems (Table XVII). The best systems allow almost 100% conversion with almost 100% yield of c -l,4-hexadiene. The best of the Ni and Rh systems known so far are still far from such amazing selectivity. The tremendous difference between the Ni system and the Co or Fe system must be linked to the difference in the nature of the coordination structures of the complexes, i.e., hexacoordinated (octahedral complexes) in the case of Co and Fe and tetra- or penta-coordinated (square planar or square pyramidal) complexes in the case of Ni. The larger number of coordination sites allows the Co and Fe complex to utilize chelating phosphines which are more effective than monodentate phosphines for controlling the selectivity discussed here. These same ligands are poison for the Ni (and Rh) catalyst system, as shown earlier. 

CoO and NiO all take the NaCl-type structure and the difference in nonstoichiometry relates to the relative stability of the formal di- and trivalent oxidation states. The stability of the trivalent state and the degree of non-stoichiometry decreases from Fe3+ to Ni2+. Hence the non-stoichiometric nature of Fcj yO is made possible by the relatively high stability of Fe3+ that is reflected in the fact that Fe2C>3 is a stable compound in the Fe-0 system, whereas M2O3 is not in the Ni-O system. This relative stability of the different oxidation states is also reflected in Figure 7.11(c). 

The presence of iron in nickel oxyhydroxide electrodes has been found to reduce considerably the overpotential for oxygen evolution in alkaline media associated with the otherwise iron free material.(10) An in situ Mossbauer study of a composite Ni/Fe oxyhydroxide was undertaken in order to gain insight into the nature of the species responsible for the electrocatalytic activity.(IT) This specific system appeared particularly interesting as it offered a unique opportunity for determining whether redox reactions involving the host lattice sites can alter the structural and/or electronic characteristics of other species present in the material. 

Morris et al. 2006). The data concerning the ternary system Al-Fe-Ti have been reviewed and discussed by Palm and Lacaze (2006) the assessments of the limiting binary systems (especially of Ti-Al and Fe-Al) have also been reported and commented. The Fe-Ni and Ti-Fe systems have been examined and discussed in papers dedicated to the assessment of Ti-Fe-Ni alloys (Cacciamani et al. 2006, Riani et al. 2006). 

In several Fe, Co, Ni alloy systems, phases having structures pertaining to the inter-related Laves type and a and // types are formed (often homogeneous in certain ranges of compositions). For compositions around 1 1, a number of solid solution phases with the CsCl-type structure and (with semi-metals) with the NiAs-type are found. 

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