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Abstract: Carbides present in ternary Fe–Al–C were investigated by the combined utilization of an X-ray diffractometer and a scanning electron microscope equipped with an energy dispersive X-ray spectrometer. The alloys were prepared by arc melting and the microstructure was homogenised by a solution annealing treatment in the temperature range 950–1050 °C for 15min. The diffraction patterns of resulting materials were analysed using a multiphase Rietveld refinement. The steel is composed of a ferritic matrix with carbides Fe3C, M23C6, and/or κ-Fe3AlC depending on the Al and C concentration. It is the first time that the existence of M23C6 ternary carbide in the Fe–Al–C system is recognized. Microprobe analyses performed revealed that the solubility of Al in M23C6 is low, with an Fe/Al ratio (in at.%) higher than 15. On the other hand, the amount of Al in the cementite is negligible and hence its lattice parameters do not depend on the Al concentration of the alloy. [ABSTRACT FROM AUTHOR]

Abstract: The elastic properties of unidirectionally solidified and of axisymmetrically deformed quasi-binary eutectic NiAl–34Cr, NiAl–9.5Mo and NiAl–0.95W alloys have been investigated by taking single crystal elastic stiffness coefficients, Young''s moduli and preferential fibre texture components into account. Also the temperature dependence of Young''s moduli of the axisymmetrically extruded rods are described and quantitatively discussed based on the model of harmonic lattice vibrations. The experimentally obtained data are in good agreement with the predicted ones. [Copyright &y& Elsevier]

Abstract: The microstructure and texture evolution of low-stacking fault energy high-manganese austenitic steel during tensile testing at room temperature was studied by means of interrupted tests. Untested material shows fully recrystallized austenitic grains and an almost random texture. During deformation, two deformation mechanisms, mechanical twinning and dislocation gliding, compete with each other. The governing mechanism of a single grain will depend on its crystallographic orientation relative to tensile direction. As a result of the strong interaction between grain orientation and twinning activity at low tensile strain, both grains with and without deformation twins can be observed. However, at high strain all the grains exhibited twin bands. Tensile tested samples were characterized by the presence of a fiber texture with the <111> and <100> directions parallel to the tensile direction. [Copyright &y& Elsevier]

The site occupancies of the transition metals Cr, Fe, and Re dissolved in NiAl of stoichiometric composition have been determined by atomic layer resolved atom probe field-ion microscopy (APFIM). The investigations were supported by X-ray diffraction studies to evaluate the lattice parameters. These are influenced by atomic size effects and constitutional lattice defects like Ni antistructure atoms in the Al sublattice and vacancies in the Ni sublattice. The APFIM results were compared with ALCHEMI data and calculated site preference energies published in the literature. Chromium additions to stoichiometric NiAl with 0.8 at% in solid solution exhibit a strong preference for Al sites. The lattice parameter of NiAl(Cr) solid solution is decreased. Iron atoms dissolved in higher concentrations of 5 at % in NiAl are almost equally distributed within both sublattices. They are possessing a weak preference for Al sites, which causes a lattice expansion of NiAl(Fe) solid solution. ALCHEMI results and site preference energy data show a strong site preference of Cr atoms for the Al sublattice. In contrast, iron atoms exhibit a weak site preference for Ni sites depending upon the stoichiometry of the NiAl host lattice.Re solutes in low concentrations of about 0.2 at % in NiAl possess a strong site preference for the Ni sublattice. The increase of the lattice parameter of NiAl(Re) is due to the pronounced size effect of Re atoms. For these species no ALCHEMI and site preference energy data are available in the literature. [Copyright &y& Elsevier]

The effect of the ternary element chromium in B2 ordered NiAl based alloys was studied by atom probe field ion microscopy. Samples of the compositions Ni50Al48Cr2, Ni49Al49Cr2, and Ni48Al50Cr2 were investigated after different heat treatments. The chromium concentrations of the NiAl matrix, measured by atom probe, increased with increasing Ni/Al ratio and heat treatment temperature. The site preference of solute Cr atoms for the Al sublattice was determined by layer resolved measurements. An antiphase boundary observed in Ni50Al48Cr2 showed a high local Cr concentration with Cr atoms substituting for Al atoms. Superdislocations in the quasi-stoichiometric Ni49Al49Cr2 were not dissociated into partial dislocations and showed no Cr segregation. These results are discussed in view of activation of a〈1 1 1〉 slip systems. [Copyright &y& Elsevier]

The constitution of the quasi–binary eutectic NiAl–Re section of the ternary Al–Ni–Re phase diagram was reinvestigated by using differential thermal analysis, metallography and scanning electron microscopy. The alloys studied were stoichiometric NiAl and various NiAl–Rex (0.75

Alloys of the B2-ordered NiAl intermetallic compound of the compositions (numbers indicate at.%) Ni50Al48Cr2, Ni49Al49Cr2, and Ni48Al50Cr2 were studied by atom probe field ion microscopy. Precipitates of α-Cr were detected in the first two compositions ranging from few nanometers as small clusters to several tens of nanometers in size. Due to the relatively low evaporation field strength of Cr atoms, these species cannot be observed directly in field ion micrographs. In Ni48Al50Cr2 samples, different precipitates containing 77 at.% Cr and 23 at.% Al are observed after annealing at 550 °C. In Ni50Al48Cr2, an antiphase boundary was imaged which showed a very high local Cr concentration, where Cr atoms substitute for Al atoms. [Copyright &y& Elsevier]

BACKGROUND AND PURPOSE Chronic heart failure (CHF) is associated with action potential prolongation and Ca(2+) overload, increasing risk of ventricular tachyarrhythmias (VT). We therefore investigated whether I(Ca) blockade was anti-arrhythmic in an intact perfused heart model of CHF. EXPERIMENTAL APPROACH CHF was induced in rabbits after 4 weeks of rapid ventricular pacing. Hearts from CHF and sham-operated rabbits were isolated and perfused (Langendorff preparation), with ablation of the AV node. VT was induced by erythromycin and low [K(+) ] (1.5mM). Electrophysiology of cardiac myocytes, with block of cation currents, was simulated by a mathematical model. KEY RESULTS Repolarization was prolonged in CHF hearts compared with sham-operated hearts. Action potential duration (APD) and overall dispersion of repolarization were further increased by erythromycin (300 µM) to block I(Kr) in CHF hearts. After lowering [K(+) ] to 1.5mM, CHF and sham hearts showed spontaneous episodes of polymorphic non-sustained VT. Additional infusion of verapamil (0.75 µM) suppressed early afterdepolarizations (EAD) and VT in 75% of sham and CHF hearts. Verapamil shortened APD and dispersion of repolarization, mainly by reducing transmural dispersion of repolarization via shortening of endocardial action potentials. Mathematical simulations showed that EADs were more effectively reduced by verapamil assuming a state-dependent block than a simple block of I(Ca) . CONCLUSIONS AND IMPLICATIONS Blockade of I(Ca) was highly effective in suppressing VT via reduction of transmural dispersion of repolarization and suppression of EAD. Such blockade might represent a novel therapeutic option to reduce risk of VT in structurally normal hearts and also in heart failure. LINKED ARTICLE This article is commented on by Stams et al., pp. 554-556 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2011.01818.x. [ABSTRACT FROM AUTHOR]

Abstract: Samples with a composition similar to the nickel-based superalloy Inconel alloy 718 were produced by electron beam melting of prealloyed powder and investigated with respect to type and composition of the strengthening precipitates. The matrix consists of γ grains orientated in nearly the same direction, almost like a single crystal. Coarse precipitates (<2μm), mostly of the (Ti,Nb)(C,N,B) type with B1 structure, are aligned along the growth direction. TEM and APFIM investigations of the γ matrix revealed very fine γ″ precipitates of around 5–10nm in size. Additionally, at small angle grain boundaries, coarser γ″ precipitates of 50–100nm in size have been observed. The 〈001〉 γ//〈001〉 γ″ and {100} γ//{100} γ″ orientation relationship between γ and γ″, known from literature [M. Sundararaman, P. Mukhopadhyay, Mater. Charact. 31 (1993) 191–196], was confirmed. Some γ′ precipitates of 2–5nm in size were observed by means of FIM. [Copyright &y& Elsevier]

Abstract: An as-cast Al-rich B2-ordered Ni–50Al–2Cr alloy was heat-treated at 550°C for 500h and then analysed by using atom probe field-ion microscopy (APFIM), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). Chromium-rich precipitates with (unexpectedly) high Al contents were detected and identified as the so-called ‘X-phase’. The α-chromium phase was also present possessing a significantly lower Al content. Nanoscale B2-ordered NiAl precipitates present in the X-phase as well as nanoscale X-phase precipitates within B2-ordered NiAl were detected. [Copyright &y& Elsevier]

Abstract: The generalized enthalpy method is a single domain method to describe heat and mass transport without the necessity to take the phase distribution or phase boundaries into account [A. Mackenbrock, K.-H. Tacke, Metall. Mater. Trans. B 26B (1996) 871–881]. Here, the temperature T is an independent parameter. The important quantity is the enthalpy H, which is used to calculate the energy flow. Hence, it is possible to simulate macroscopic multi-phase systems with reduced computational effort. Calculations were carried out, describing solidification and microstructure formation during continuous casting of peritectic steel grades. The binary Ti–Al system with its numerous intermetallic phases is modeled to describe solidification and phase formation at heterogenous laser welded interfaces. [Copyright &y& Elsevier]

Fully dense composite materials of M3/2 tool steel reinforced with 5 and 8 vol.-% of niobium carbide were developed using the powder metallurgy route. The consolidated materials exhibited a fine and uniform microstructure consisting of a fine dispersion of carbide particles in a matrix of ferrite/martensite. The 0·2% yield strength up to 600°C was evaluated in compression. The slight increase observed after reinforcement by NbC particles in as hipped materials suggests that the martensite has the major contribution to the strength. After tempering, the reinforced materials showed a moderate increase in yield stress at room temperature with respect to the unreinforced M3/2. This increase is attributed to reinforcement mechanisms associated with niobium carbide. PM/1175 [ABSTRACT FROM AUTHOR]

Abstract: The influence of the microstructure on the creep properties of a Ti–46.8Al–1Mo–0.2Si was studied by stress change tests in compression at temperatures ranging from 700 to 1000°C. The material produced by arc melting exhibited a structure of coarse lamellar grains in the as-cast condition that transformed to an equiaxed near γ microstructure after processing by hot extrusion at 1300°C. The high temperature deformation data strongly depended on the type of microstructure present in the material. For each microstructure, deformation data were correlated by means of a conventional power law creep relation. The analysis showed an activation energy of about 400kJ/mol for both microstructures. On the other hand, each starting microstructure showed a different stress exponent. TEM analysis of deformed samples allowed the correlation of the stress exponents to different mechanisms controlling deformation. [Copyright &y& Elsevier]

The stress–strain behaviour as a function of temperature as well as the critical temperatures of the D03↔B2 and B2↔A2 structural transitions were studied on quaternary Fe3Al-based Fe-26 at.% Al–4 at.% Ti–X alloys containing 2 or 4 at.% of X=V, Cr, Nb, or Mo. The microstructures of the alloys were characterized by light optical microscopy, transmission electron microscopy (TEM), and electron-probe microanalysis (EPMA). The alloys containing V, Cr, or Mo form solid solutions, whereas additions of 2 and 4 at.% Nb result in the formation of Laves phase precipitates. A comparison of the temperatures of the maximum of the flow stress anomaly and the D03↔B2 transitions determined in compression tests and by differential thermal analysis (DTA), respectively, clearly reveals that there is no correlation between the stress anomaly and the degree of ordering. The effect of the different alloying elements on the order-disorder transition temperatures of the quaternary alloys is discussed and compared with that of respective ternary Fe3Al-X alloys without Ti. [Copyright &y& Elsevier]

The influence of microstructure of the two-phase alloyTi–46Al–1Cr–0.2Si on the oxidation behavior in air between600 and 900°C was studied. The oxidation rate, type of scale, and scalespallation resistance were strongly affected by the type of microstructure,i.e., lamellar in as-cast material and duplex after extrusion at1300°C. The oxidation rate was affected by the size and distribution ofthe α2-Ti3Al phase, being faster for the extrudedmaterial with coarse α2-Ti3Al. The type of oxide scaledetermines the spalling resistance. Cast material developed a uniform scalethat spalled off after short exposure times at 800 and 900°C when a criticalthickness was reached. The extruded material presented a heterogeneous scalewith predominant thick regions formed on γ-TiAl-α2-Ti3Algrains and thin scale regions formed on γ-TiAl grains. Thistype of scale could permit an easier relaxation in the matrix of stressesgenerated by both thermal-expansion mismatch between scale and alloy andoxide growth, resulting in a higher spallation resistance. [ABSTRACT FROM AUTHOR]

Pulmonary vein isolation (PVI) using cryoenergy is safe and efficient for treatment of atrial fibrillation (AF). Pre-existing upper gastrointestinal (GI) pathologies have been shown to increase the risk for AF. Therefore, this study aimed at assessing incidental pathologies of the upper GI tract in patients scheduled for PVI and to analyse the impact of patients' characteristics on PVI safety outcome. In 71 AF patients, who participated in the MADE-PVI trial, oesophagogastroduodenoscopy and endosonography were prospectively performed directly before and the day after PVI to assess pre-existing upper GI pathologies and post-interventional occurrence of PVI-associated lesions. Subgroup analysis of the MADE-PVI trial identified clinically relevant incidental findings in 53 patients (74.6%) with age > 50 years being a significant risk factor. Pre-existing reflux oesophagitis increased risk for PVI-associated mediastinal oedema, while patients already treated with proton pump inhibitors (PPI) had significantly fewer mediastinal oedema. Our results suggest that AF patients with pre-existing reflux oesophagitis are at higher risk for PVI-associated mediastinal lesions, which is decreased in patients with constant PPI-treatment prior to PVI. Since PVI-associated mediastinal lesions are regarded as surrogate parameter for an increased risk of the fatal complication of an oesophago-atrial fistula, our findings hint at a beneficial effect of pre-interventional prophylactic PPI-treatment to reduce risk for PVI-associated complications. German Clinical Trials Register (DRKS00016006; date of registration: 17/12/2018). [ABSTRACT FROM AUTHOR]

Aims In atrial fibrillation, increased function of the Na + /Ca 2 + -exchanger (NCX) is one among several electrical remodeling mechanisms. Methods/results Using the patch-clamp- and Ca 2 + imaging-methods, we investigated atrial myocytes from NCX-homozygous-overexpressor (OE)- and heterozygous-knockout (KO)-mice and their corresponding wildtypes (WT OE ; WT KO ). NCX mediated Ca 2 + extrusion capacity was reduced in KO and increased in OE. There was no evidence for structural or molecular remodeling. During a proarrhythmic pacing-protocol, the number of low amplitude delayed afterdepolarizations (DADs) was unaltered in OE vs. WT OE and KO vs. WT KO . However, DADs triggered full spontaneous action potentials (sAP) significantly more often in OE vs. WT OE (ratio sAP/DAD: OE:0.18 ± 0.05; WT OE :0.02 ± 0.02; p < 0.001). Using the same protocol, a DAD triggered an sAP by tendency less often in KO vs. WT KO ( p = 0.06) and significantly less often under a more aggressive proarrhythmic protocol (ratio sAP/DAD: KO:0.01 ± 0.003; WT KO: 0.12 ± 0.05; p = 0.007). The DAD amplitude was increased in OE vs. WT OE and decreased in KO vs. WT KO . There were no differences in SR-Ca 2 + -load, the number of spontaneous Ca 2 + -release-events or IKACh/IK1. Conclusions Atrial myocytes with increased NCX expression exhibited increased vulnerability towards sAPs while atriomyocytes with reduced NCX expression were protected. The underlying mechanism consists of a modification of the DAD-amplitude by the level of NCX-activity. Thus, although the number of spontaneous Ca 2 + -releases and therefore DADs is unaltered, the higher DAD-amplitude in OE made a transgression of the voltage-threshold of an sAP more likely. These findings indicate that the level of NCX activity could influence triggered activity in atrial myocytes independent of possible remodeling processes. [ABSTRACT FROM AUTHOR]

BACKGROUND AND PURPOSE Chronic heart failure (CHF) is associated with action potential prolongation and Ca2+ overload, increasing risk of ventricular tachyarrhythmias (VT). We therefore investigated whether ICa blockade was anti-arrhythmic in an intact perfused heart model of CHF. EXPERIMENTAL APPROACH CHF was induced in rabbits after 4 weeks of rapid ventricular pacing. Hearts from CHF and sham-operated rabbits were isolated and perfused (Langendorff preparation), with ablation of the AV node. VT was induced by erythromycin and low [K+] (1.5mM). Electrophysiology of cardiac myocytes, with block of cation currents, was simulated by a mathematical model. KEY RESULTS Repolarization was prolonged in CHF hearts compared with sham-operated hearts. Action potential duration (APD) and overall dispersion of repolarization were further increased by erythromycin (300 µM) to block IKr in CHF hearts. After lowering [K+] to 1.5mM, CHF and sham hearts showed spontaneous episodes of polymorphic non-sustained VT. Additional infusion of verapamil (0.75 µM) suppressed early afterdepolarizations (EAD) and VT in 75% of sham and CHF hearts. Verapamil shortened APD and dispersion of repolarization, mainly by reducing transmural dispersion of repolarization via shortening of endocardial action potentials. Mathematical simulations showed that EADs were more effectively reduced by verapamil assuming a state-dependent block than a simple block of ICa. CONCLUSIONS AND IMPLICATIONS Blockade of ICa was highly effective in suppressing VT via reduction of transmural dispersion of repolarization and suppression of EAD. Such blockade might represent a novel therapeutic option to reduce risk of VT in structurally normal hearts and also in heart failure. LINKED ARTICLE This article is commented on by Stams et al., pp. 554-556 of this issue. To view this commentary visit [ABSTRACT FROM AUTHOR]

Abstract: The influence of temperature and strain rate on the evolution of the retained austenite content during plastic straining has been studied by tensile tests performed at 4×10−4, 10−2 and 0.4s−1 between −100 and 450°C. Up to 150°C, the austenitic volume fraction mechanically transformed decreases with increasing testing temperature being almost independent of strain rate. In contrast, above 150°C the martensite transformation depends on testing temperature and strain rate since it is related to the ability of carbon atoms for pinning dislocations. [Copyright &y& Elsevier]

The article examines the influence of temperature on the deformation mechanisms of a Fe-16.5Cr-8Mn-3Ni-2Si-1Cu-0.25N or high nitrogen-manganese austenitic stainless steel alloy using X-ray diffraction and transmission electron microscopy measurements. The recrystallized samples were deformed under tension in which deformation to failure has resulted in extensive transformation plasticity (TRIP). The study reveals that dislocation slip, and some deformation induced twinning (TWIP) were observed.

Abstract: Five quaternary Fe–Al–B–M (M=Ti, Hf, Zr, V, W) alloys based on Fe3Al with strengthening boride precipitates were produced by vacuum induction melting. The alloys were investigated with respect to their microstructure and mechanical behaviour up to 1000°C. The mechanical properties were determined by tensile tests, 4-point-bending tests, high-temperature compression tests up to 1000°C as well as creep tests at 650 and 750°C. Microstructural and phase analysis were carried out by light optical microscopy, scanning electron microscopy, X-ray diffraction analysis and differential thermal analysis. The alloys were tested in the as-cast state, after homogenisation at 1200°C for 48h and after annealing at 800°C for 624h. Compared to a corresponding binary alloy the examined alloys exhibit significantly improved mechanical high-temperature properties as well as stable microstructures without considerable loss of ductility. [Copyright &y& Elsevier]

Abstract: In this paper results on the microstructures and mechanical properties of Fe3Al-based Fe–Al–C alloys with strengthening precipitates of the perovskite-type κ-phase Fe3AlC x are presented. The alloys are prepared by vacuum induction melting and cast into Cu-moulds. The composition of the Fe3Al matrix of the investigated Fe–Al–C alloys varies between 23 and 29at.% Al. The ternary C-additions range from 1 to 3at.%. The microstructures of the alloys are characterised by means of light optical microscopy (LOM). Phase identification is performed by means of X-ray diffraction (XRD). The strength of the alloys as a function of temperature is determined through compression tests. The room-temperature ductility is evaluated by tensile tests. The fracture surfaces of the tensile specimens are analysed using scanning electron microscopy (SEM). [Copyright &y& Elsevier]

Abstract: A binary Fe3Al alloy is investigated with respect to hot deformation behavior and microstructural as well as microtextural modifications. Applying the hot deformation simulator (WUMSI) to hot rolling conditions in the A2 and B2-order regimes in combination with data analysis, significant changes in deformation behavior are identified. These conditions are selected for performing hot rolling experiments. The differences in microstructure are investigated. On the basis of microtexture investigations by means of electron backscatter diffraction (EBSD) differences concerning orientation gradients and sub-grain structures are found. A model of combined order-related and non-order related effects is proposed explaining the observed material behavior. The information gained is the basis for the optimization of the thermomechanical treatment to produce ductile Fe3Al sheet material. [Copyright &y& Elsevier]

Abstract: A Fe–26Al–5Cr (at.%) single-phase (α:A2/B2/D03) alloy and two-phase (α+TiC) alloys with different amounts of TiC particles have been hot rolled at 800°C and the kinetics of static recrystallisation have been studied. In the alloys with a high amount of TiC, needle-like TiC of more than 1μm in length formed during cooling after homogenisation in the α single-phase region and coarsened during hot rolling. The large particles cause particle stimulated nucleation (PSN) and hence accelerate recrystallisation. In order to accomplish both strengthening by precipitates and inhibition of recrystallisation that deteriorates room-temperature ductility, a thermo-mechanical treatment consisting of hot deformation with a low amount of precipitates and a subsequent heat treatment for further precipitation is proposed. This process is difficult to carry out in the (Fe–26Al–5Cr)–TiC system due to the high precipitation temperature of TiC. The precipitation temperature is significantly decreased by replacing TiC by VC or MoC. [Copyright &y& Elsevier]

Abstract: The mechanical properties of Fe–15Al (in at.%) and Fe–26Al based alloys with alloying additions are investigated. The alloys contain 1at.% C and 2 or 4at.% Ti, V, Nb or Ta. Preliminary information on the mechanical properties of the investigated alloys is provided by means of hardness tests. The mechanical testing of alloys is carried out in compression as well as in tension. Compression tests are carried out at room temperature and at elevated temperatures including the temperature range of the yield stress anomaly. The tensile tests are performed in order to determine the room temperature ductility and high temperature tensile strength at temperatures of possible industrial applications. The investigation of the fracture surfaces of ruptured tensile specimens is performed by means of scanning electron microscopy (SEM). [Copyright &y& Elsevier]

Texture measurements were carried out on a Fe–26Al–5Cr alloy that was deformed by warm rolling at temperatures above and below the stress anomaly temperature in order to obtain information about a possible change of slip systems around that temperature. Special attention was paid to the initial microstructure, temperature during rolling and recrystallisation problems. Textures were determined by automatic crystal orientation mapping (ACOM) using electron backscatter diffraction (EBSD), which allows separation of measurement data from recrystallised and unrecrystallised fractions in the microstructure. A clear difference in texture evolution appears above and below the stress anomaly temperature; the most preferred orientations after rolling at 600 and 400 °C are ∼{5 5 7}〈1 1 0〉 and ∼{1 1 1}〈2 1 1〉, respectively. This result suggests that the shear fraction of the active {1 1 2}〈1 1 1〉 slip systems increases with respect to that of the {1 1 0}〈1 1 1〉 slip systems with increasing temperature around the stress anomaly temperature. [Copyright &y& Elsevier]

The micro- and nano-structure of a NiAl–Re alloy with 1 at.% Re has been investigated by means of atom probe field ion microscopy (APFIM) and by scanning electron microscopy. The effect of heat treatments on this alloy were studied for annealing temperatures at 1000 °C in a time interval of 10–1000 h, and at 1300 °C for 1000 h. The results were compared with those from the as-cast samples. Rhenium contents of the NiAl matrix were determined by APFIM. It was found that the Re concentration in the primary NiAl crystals decreases with increasing annealing time. Layer-resolved atom probe measurements were performed in order to determine the site occupancy of Re atoms in the NiAl superlattice. The results clearly showed a site preference for the Ni sublattice. [Copyright &y& Elsevier]

Iron aluminides are known for their resistance to high temperature corrosion. There is a need to improve the strength at high temperatures. For this, Fe–Al–M–C (M=Ti, V, Nb, Ta) alloys with strengthening carbides and Laves phase are investigated. The aim of the present study is to characterise the high temperature stability of the strengthening particles. This paper presents results on microstructure and constitution of these alloys. The alloys contain 15 or 26 at.% Al, 2 at.% Ti, V, Nb, or Ta, and 1 at.% C. The alloys are prepared by vacuum induction melting and cast into Cu-moulds. The samples are investigated in the as-cast state and after heat treatment at 1000 °C. Microstructural analysis is performed by light optical microscopy (LOM), scanning electron microscopy (SEM), electron probe micro-analysis (EPMA), and X-ray diffraction analysis (XRD). The experimentally determined phase equilibria are compared with thermodynamic calculations using Thermo-Calc. [Copyright &y& Elsevier]

Pyrite films were prepared using the pure elements as source materials: thin iron films were evaporated on quartz substrates and exposed to a sulfur plasma. The process was controlled by a transmission measurement. X-ray spectroscopy was used to characterize the films and preliminary optical and electrical measurements were carried out. [ABSTRACT FROM AUTHOR]