Metal Dilution Research Articles

Process parameter determination for consumable nozzle electroslag welding

The process parameters and weld dimensions in consumable nozzle electroslag welding were calculated using the two dimensional heat flow condition based on Eregin's concept. The weld metal dilution under these operating variables was also computed. Experiments revealed that calculated parameters produce sound welded joints and that there is fairly good agreement between the calculated and observed results.MST/1103

Magnetic Behavior of Spin-Crossover Iron(III) Complexes Adsorbed on the Surface of Silicon Dioxide and Metal Dilution Effects on Magnetism

Abstract The effects of metal dilution and adsorption on the surface of silicon dioxide on the spin-crossover behavior of [Fe(acpa)2]PF6, [Fe(acpa)2]BPh4, and [Fe(bzpa)2]PF6, which undergo fast spin-state interexchange on the 57Fe Mössbauer timescale have been studied by using 57Fe Mössbauer and EPR spectroscopies, powder X-ray diffraction and magnetic susceptibility, where Hacpa is N-(1-acetyl-2-propylidene)-2-pyridylmethylamine and Hbzpa N-(1-benzoyl-2-propylidene)-2-pyridylmethylamine. Solid solution compounds, [FexCo1−x(acpa)2]BPh4(x=0.035 and 0.074) and [Fe0.05Co0.95(bzpa)2]PF6 exhibit spin-crossover phenomena. No difference in the spin-state interexchange rate is observed between the diluted compound and the corresponding undiluted one as far as the rates are evaluated by Mössbauer spectroscopy. Mössbauer spectra for [Fe0.074Co0.926(acpa)2]PF6 exhibit only a pair of quadrupole doublets assigned to the low-spin state in the temperature range from 78 to 298 K. The spin-state interexchange rates for [Fe(acpa)2]BPh4 and [Fe(bzpa)2]PF6 adsorbed on the surface of silicon dioxide become slow compared to those for the corresponding pure complexes and the narrowing of the spin-state transition temperature range is observed. On the contrary no detectable differences in the spin-state interexchange rates are observed between the Mössbauer spectra for [Fe(acpa)2]PF6 adsorbed on the surface of silicon dioxide and that for the pure complexes. These observations are interpreted in terms of a spin-state transition behavior in these complexes which is affected by the packing state in the solid state, which is dependent on the characteristic structure of the respective complex.

“Transparent” metals: preparation and characterization of light-transmitting palladium, rhodium, and rhenium films

We show that the principles that govern the preparation and properties of “transparent” platinum films apply also to films of palladium, rhodium and rhenium. Films of these metals, of 42–60 nm thickness, having a metal volume fraction between 0.3 and 0.5, transmit more light than equivalent, dense metal films of identical metal loadings per unit area. The films are prepared by photoelectrodeposition onto p-InP (100) photocathodes, from ∼5×10 −5 M solutions of the metal ions in 1 M HClO 4, under mass-transport limited conditions, at deposition rates of ∼ 2 nm/h. The “transparent” rhodium, rhenium and palladium films exhibit their normal catalytic behavior and have normal crystal structures. While the “transparent” rhodium and palladium films, like the bulk metals, are stable in air, the rhenium films oxidize over a period of days to form films that are either truly amorphous or consist of crystallites of less than 1 nm diameter. The spectroellipsometrically measured dielectric functions of these films in air are analyzed, in the framework of the Bruggeman effective medium approximation, to yield film thicknesses, metal volume fractions, and mean depolarization factors. The respective depolarization factors of Rh, Pd, and Re indicate dendritic, particulate, and platelet microstructures, consistent with the structures observed by transmission electron-microscopy. With the spectroellipsometrically derived, substantially divergent, depolarization factors for the different microstructures, one obtains consistent relationship among film thicknesses, metal volume fractions, and the optical properties. Absorption in tenuous films, of constant metal loading but different microstructures, tends to different finite values strongly dependent on microstructure, in the limit of infinite metal dilution.

Influence of Process Variables in Flux Cored Arc Welding of Hardfacing Deposits

A lack of knowledge and objective data on the effects of welding process variables in the application and performance of weld deposited hardfacings has led to many past failures and a subsequent mistrust of the technology. This paper sets out, first, to review both the influence of welding process variables in hardfacing and the important characteristics and properties which determine the effective performance of a hardfacing deposit. Second, the results are presented of a full factorial experiment, which was performed in an effort to evaluate and interpret the effects of arc current, voltage, and polarity, as well as of travel speed, torch stand-off distance, and preheat, on the nature and properties of a commercial flux cored arc welded hardfacing deposit. In this programme, the effects of the welding parameters were evaluated with the aid of a number of computer analyses, with arc current, voltage, and polarity being shown to have the greatest effect: a high arc current (360 A) gives the most satisfactory deposit in terms of weld metal dilution, hardness, and porosity, as well as of both deposition rate and efficiency, provided that electrode negative arc polarity is used, together with a low (24 V) arc voltage. In attempting to achieve more cost effective use of hardfacings in abrasive wear resistant applications, both the potential of this approach and the value of the results obtained are clearly demonstrated.

ChemInform Abstract: EFFECT OF METAL DILUTION ON THE SPIN‐CROSSOVER BEHAVIOR IN (FEXM1‐X(PHEN)2(NCS)2) (M = MN, CO, NI, ZN)

Chemischer InformationsdienstVolume 13, Issue 49 Physical Organic Chemistry ChemInform Abstract: EFFECT OF METAL DILUTION ON THE SPIN-CROSSOVER BEHAVIOR IN (FEXM1-X(PHEN)2(NCS)2) (M = MN, CO, NI, ZN) P. GANGULI, P. GANGULISearch for more papers by this authorP. + GUETLICH, P. + GUETLICHSearch for more papers by this authorE. W. + MUELLER, E. W. + MUELLERSearch for more papers by this author P. GANGULI, P. GANGULISearch for more papers by this authorP. + GUETLICH, P. + GUETLICHSearch for more papers by this authorE. W. + MUELLER, E. W. + MUELLERSearch for more papers by this author First published: December 7, 1982 https://doi.org/10.1002/chin.198249060AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume13, Issue49December 7, 1982 RelatedInformation

Effect of metal dilution on the spin-crossover behavior in [FexM1-x(phen)2(NCS)2] (M = Mn, Co, Ni, Zn)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of metal dilution on the spin-crossover behavior in [FexM1-x(phen)2(NCS)2] (M = Mn, Co, Ni, Zn)P. Ganguli, P. Guetlich, and E. W. MuellerCite this: Inorg. Chem. 1982, 21, 9, 3429–3433Publication Date (Print):September 1, 1982Publication History Published online1 May 2002Published inissue 1 September 1982https://doi.org/10.1021/ic00139a032RIGHTS & PERMISSIONSArticle Views424Altmetric-Citations69LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (570 KB) Get e-Alerts Get e-Alerts

Spin crossover in solid solution

The temperature dependent high spin (HS) ⇌ low spin (LS) transition, otherwise called spin crossover, has been well established for many first-row transition metal complexes, particularly for complexes of iron(II) [1]. The phenomenon has been observed mostly in the crystalline state, but also in solution. The spin crossover characteristics have been found to depend on various chemical influences, such as ligand substitution, the nature of the non-coordinating anion and the crystallizing solvent. It has been shown by 57Fe Mössbauer spectroscopy that the spin crossover behaviour in the solid solutions of [Fe xZn 1−x(2-pic) 3] Cl 2·EtOH (2-pic = 2-picolylamine) is also susceptible to metal dilution [2, 3]. At a given temperature, the HS state becomes favoured over the LS state with decreasing x. This may be qualitatively interpreted on the grounds of a cooperative domain model [2]. A phenomenological thermodynamic treatment [4] yields estimates of the changes of enthalpy and entropy as well as the domain size. A statistical model has also been successfully applied, which also allows to estimate the domain size and, in addition, an average effective frequency of the metalligand vibrational modes in each of the two spin states. Mössbauer effect studies of the solid solution of [Fe xCo 1−x(2-pic) 3] Cl 2·EtOH show similar results. The relative stability of the HS state, at a given temperature, also increases with decreasing x. The Fe x/CO 1−x/2-pic system, however, shows higher transition temperatures, at a given x, than the Fe x/Zn 1−x/2-pic system, apparently due to the more rigid lattice of the former system. The effect of metal dilution in solid solutions of [Fe xM 1−x(phen) 2(NCS) 2] (M = Co, Mn, Ni) as studied by Mössbauer spectroscopy [5] follows the same line: at a given temperature, the 5T 2(O h) state becomes favoured over the 1A 1(O h) state upon lowering x.

Mössbauer effect study of the electronic ground state of iron(II) in [ 57Fe xM 1−x(bipy) 3](ClO 4) 2 (M = Mn, Ni, Zn) and [ 57Fe xM 1−x(phen) 3](ClO 4) 2 (M = Ni, Zn) at very lowiron concentrations

Earlier work in our laboratory on the effect of metal dilution on the 5T 2(O h ⇌ 1A 1(O h) equilibrium in polycrystalline spin crossover systems of iron(II) has shown that the relative stability of the high spin state, 5T 2(O h), at a given temperature, increases markedly with decreasing iron concentration. These results have initiated the present work. Using 57Fe Mössbauer spectroscopy, we have investigated the electronic ground state of iron(II) in the highly diluted solid solutions [Fe xM 1−xL 3] with L = bipy, M = Mn, Ni, Zn, x ≲ 0.005 and L = phen, M = Ni, Zn, x ≲ 0.005. Although the critical field potential (V c) of the pure iron complexes, which are known to be low spin, is reported to be not far from the crossover point V c = P ( P , the mean spin pairing energy), the effect of metal dilution does not reduce the difference ¦ V c - P ¦ sufficiently as to thermally populate the 5T 2(O h) state at room temperature to any noticeable extent. ¦ V c - P ¦ has been estimated to be ≳ 1200 cm −1. The quadrupole splitting and the resonance line width are nearly the same in the pure compounds and the solid solutions. The isomer shift, however, is found to increase slightly in the order M = Fe < Ni < Zn < Mn, and parallels the increase in the ionic radii of the M ++ host ions.

Some Experimental Evidence of Collision Processes in Spectrochemical Analysis

Synthetic silicate melts of CaSiOa and CaMg(SiO3)2 and 20 intermediate mixtures were used as standards for Calibrating a spectrochemical analysis method for CaO and MgO by the Ge metal dilution method previously described. The slope of log RET: log C curves showed large departures from unity, as follows: 0.82, 0.73, 0.62, and 0.24 respectively for Mg I 2779, Mg I 2776, Mg II 2795 and Mg II 2798. Curves for all Si lines showed slopes greater than unity: 1.27, 1.8, 4.22, and 6.39 respectively for Si I 2528, Si I 2987, Si I 2881, and Si I 2631. These results had earlier been interpreted as evidence for the effect of “collisions of the second kind” on intensity of light radiated by a DC arc source, whereby Mg and Si atoms collide and excitation energy is transferred from Mg to Si. Si intensity is enhanced and Mg weakened as the population of Mg atoms increases in the arc. The experimental log RET: log C curves are presented for the series of diopside: psuedo-wollastonite standards. The only variable in the standards is the MgO/CaO ratio. The amounts of these two substances vary such that their sum remains approximately constant. The Ge matrix and atmosphere are constant, and the SiO2 content is nearly so. Since the slopes of the Ca line curves are nearly unity, Mg and Si atoms are concluded to be involved in the energy exchanging collisions.