Effect Of Fe Content Research Articles

Effect of Fe Content on the Contact Resistance of Electroplated Au-Fe Alloy Layers

1. This work was financially supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT and Future Planning (grant No. NRF-2014R1A1A1007848).

The effect of Fe content on dielectric and relaxation characteristics in TbFexMn1-xO3

Various ceramic composites of TbFexMn1-xO3 (x = 0, 0.25, 0.5, 0.75) were prepared by conventional solid-state reaction. The electrical properties such as dielectric constant, loss and resistivity have been studied as a function of the temperature from 77 to 400 K and the frequency from 0.1 to 1000 kHz. The XRD and SEM for these four types of materials show similar patterns with the increasing of the Fe concentration. Instead, the dielectric constant and loss for them will change dramatically in properties. The figures of all samples display two distinct semicircular arcs in the Nyquist plots at 300 K and all figures located at high frequency region are independent of the applied ac biases. By analyzing the values of the activation energy, it is found that the origin of the relaxation in dielectric loss is related to the changing of octahedral structure.

Effect of Fe content on Cu2FexZn1−xSnS4 single crystals fabricated by flux growth method

High quality micron-sized Cu2FexZn1−xSnS4 single crystals have been successfully fabricated by flux growth method using CuS, FeS, ZnS and SnS as the raw materials and CsCl as the fluxing agent. The effects of Fe contents on the morphology, structure and optical properties of Cu2FexZn1−xSnS4 single crystals were investigated. X-ray diffraction and Raman analyses reveal that the kesterite and stannite phases coexist in the Cu2FexZn1−xSnS4 crystals, and peak splittings of (2 0 4) and (3 1 2) are observed for the sample with x = 0.2. The optical absorption spectra reveal that the optical bandgap of the single crystal samples has little dependence on the Fe content due to the coexistence of the kesterite and stannite phases. The bandgap of the Cu2FexZn1−xSnS4 single crystal generally locates between 1.672 and 1.716 eV. Though the bandgap is not ideal as the absorber for single-junction solar cells according to the S–Q limit, it is an ideal material for the top cell in tandem solar cells and solar-driven water splitting.

Effects of Fe-Ni solvent with different Fe contents on the boron concentration in colorless diamonds

In this paper, high-quality colorless diamonds were successfully synthesized by temperature gradient method (TGM) in China-type cubic anvil high-pressure apparatus (CHPA) at 6.0 GPa and 1340 °C. High-purity graphite was used as carbon source and the Fe-Ni alloys with different Fe contents were used as the solvent-catalyst for diamond synthesis. The effects of Fe content (high-Fe-type and low-Fe-type) on boron concentration were specially investigated. All the colorless diamonds exhibit the typical boron-related absorption peaks of 2802 cm−1 in infrared (IR) absorption spectra, but the boron concentrations are different. Compared with the low-Fe-type alloy solvent, it is more difficult for boron atoms to incorporate into diamond lattice in high-Fe-type alloy solvent system. This work provides a new approach to control the boron concentration in colorless diamonds and synthetic high-purity diamond crystal.

The effect of Fe contents on the local structure and crystallization behavior of SiO2–CaO–P2O5–Fe2O3 glasses

The glass and glass ceramics containing SiO2–CaO–Fe2O3–P2O5 were prepared by sol–gel method. The influence of the Fe contents on the crystallization and local structure of the glass and glass ceramics was systematically investigated. The crystal structure of the glass ceramics was identified by XRD characterization. Hematite phase can be precipitated from the glass matrix in all glass ceramics with various Fe contents, and the crystallographic parameters of hematite were determined by XRD Rietveld refinement. The crystallization kinetics of the glasses was investigated in detail. Relative low activation energies were obtained at low Fe contents. The local structure evolution of the glass and glass ceramics has been studied in-depth by means of FTIR and Mossbauer spectroscopy. Fe element is present both as network former and network modifier which significantly influenced the crystallization activation energies of the glasses. The results of this work may be of great significance for the material design and practical applications of bioactive magnetic glass ceramics for hyperthermia.

Effects of Fe substitution for Co on the thermal, magnetic, and mechanical properties of the Co-Fe-B-Si-Mo alloy system

The effects of Fe content on the thermal, magnetic, and mechanical properties of a Co72B19.2Si4.8Mo4 alloy were studied. Amorphous soft magnetic alloys of (Co1−xFe x )72 B19.2Si4.8Mo4 (0 ≤ x ≤ 1) with 3-mm widths and 27 - 30 μm thicknesses were obtained by using the melt spinning technique. The crystallization temperature (T x ) for each alloy was measured by using differential scanning calorimetry (DSC). All ribbons were identified as fully amorphous by using X-ray diffraction (XRD). The magnetic properties of the amorphous ribbons were measured by using a vibrating sample magnetometer (VSM). The Fe-only ribbon (x = 1) showed the highest saturation magnetization of 1.15 T in these alloys. Also, the nano-hardness (H nanoindentation ), and Young’s modulus (E) were evaluated by using nano-indentation experiments, and Co21.6Fe50.4B19.2Si4.8Mo4 (x = 0.7) show a nano-hardness (H nanoindentation ) of 18.92 GPa.

Manufacture and characteristics of Al2O3 composite coating on steel substrate by SHS process

Many steel components are needed to be reinforced on their surface to have a high abrasive resistance and corrosion resistance. Based on self-propagating high-temperature synthesis, a process to making Al2O3 composite coatings on mild steel substrate in atmospheric environment with the help of simple auxiliary facilities was developed successfully. A pre-coated bilayer coating was employed. The effects of Fe content in pre-coated transition layer on phase composition, porosity and interfacial bonding were studied using scanning electron microscopy (SEM), energy-dispersive spectrum (EDS) and X-ray diffraction (XRD). The thermal shock resistance and abrasive resistance were investigated. When Fe content changes from 0 wt% to 50 wt%, the bond quality at first becomes better and then worse gradually. When Fe content is less 20 wt%, there is a small gap between the transition layer and the substrate; when Fe contents are 30 wt% and 40 wt%, working layer, the transition layer and the substrate bond together well. The working layer is mainly composed of Al2O3, Fe–Cr and Al(Cr)2O3 phases and has a dense structure with porosity of less than 1%. The coating has a good thermal shock resistance and abrasive resistance. The abrasive resistance of the working layer is about ten times that of the substrate.

Effect of Fe content, sintering temperature and powder processing on the microstructure, fracture and mechanical behaviours of Ti-Mo-Zr-Fe alloys

The present work studies the effect of iron on the microstructural characterization and mechanical properties of Ti12Mo6ZrxFe alloys that fabricated by two different techniques elemental blend (EB) at 600 MPa and mechanical alloying (MA) at 600 MPa and 900 MPa with different sintering temperatures. The Ti12Mo6ZrxFe (x = 1, 2, 3 and 4 wt.%) alloys were investigated to develop new biomedical materials used for dental implant application. The microstructure, residual porosity and the mechanical properties of the sintered Ti12Mo6ZrxFe alloys were investigated by using optical microscopy, X-ray diffraction (XRD), Scanning Electron Microscopy (SEM(, Energy dispersive X-ray (EDX), microhardness and bending stress–strain curves. The results indicated that addition of Zr and a small amount of Fe improves the β-phase stability and improving the properties of Ti-Mo alloy. In addition, with increasing the sintering temperatures, the microstructure became more homogeneous for β phase, which decreases in the modulus and strength. The Mechanical alloying allows highly homogeneous composition and particle morphology. Bending strength in EB is much higher than MA techniques. Increasing of compaction pressure during MA technique increases the bending strength and decreases the porosity. Moreover, the Ti12Mo6Zr2Fe alloys exhibited higher bending strength/modulus ratios.

Three-dimensional characteristics of Fe-rich intermetallics in gravity-cast Al-6Si alloys

Fe-rich intermetallics, especially β-Fe phase, usually forming in the microstructure of cast aluminum alloys, are very detrimental to mechanical properties. In the present work, the effects of Fe content on phase transformation and microstructures were analyzed using a 3D X-ray microscope. Based on the high-resolution 3D X-ray computed tomography, the 3D characteristics of Fe-rich intermetallics and micropores in the gravity-cast Al-6Si alloys with different Fe contents were investigated. In addition, the effect of intermetallics on the microporosity was discussed. The results show that with increasing the Fe content from 0.10wt.% to 0.60wt.%, the volume fraction of Fe-rich intermetallics and the volume of the largest size Fe-rich intermetallic increased, and the 3D morphology of intermetallics changed from fine flake to network aggregation. As the Fe contents increased, the shrinkage pores were characterized, which were rather complex due to the micropores promoted by the intermetallics interactions.

Effect of Fe-Content on the Mechanical Properties of Recycled Al Alloys during Hot Compression

It is unavoidable that Fe impurities will be mixed into Al alloys during recycling of automotive aluminum parts, and the Fe content has a significant effect on the mechanical properties of the recycled Al alloys. In this work, hot compression tests of two Fe-containing Al alloys were carried out at elevated temperatures within a wide strain rate range from 0.01 s−1 to 10 s−1. The effect of Fe content on the peak stress of the stress vs. strain curves, strain rate sensitivity and activation energy for dynamic recrystallization are analyzed. Results show that the recycled Al alloy containing 0.5 wt % Fe exhibits higher peak stresses and larger activation energy than the recycled Al alloy containing 0.1 wt % Fe, which results from the fact that there are more dispersed AlMgFeSi and/or AlFeSi precipitates in the recycled Al alloy containing 0.5 wt % Fe as confirmed by SEM observation and energy spectrum analysis. It is also shown that the Fe content has little effect on the strain rate sensitivity of the recycled Al alloys.

Effect of Fe content on atomic and electronic structure of complex oxides Sr(Ti,Fe)O3 − δ

We present a study of the electronic and atomic structure of two series of SrTi1−xFexO3−δ (STFO) powders with different Fe content produced by two different methods, spray pyrolysis or modified Pechini synthesis, by means of soft X-ray absorption spectroscopy. Partial substitution of Ti by Fe atoms in SrTiO3 were found to cause asymmetric distortion of TiO6 octahedrons, which increases with increasing Fe content that may violate the cubic symmetry of STFO. The presence mainly of Fe3+states in octahedral environment at small concentration of Fe atoms along with essentially smaller content of Fe4+ states in octahedral environment where the latter contribution increases with increasing Fe content was traced. It is found that the modified Pechini method allows to synthesize more stable structures but a tendency of the SrOx formation in the structure prepared by this technique was marked. The spray pyrolysis method gives the structure free of SrO precipitates but the presence of Fe3+ states in tetrahedral environment with Fe content higher than 50% and even a certain amount of Fe2+ ions in an octahedral environment at concentrations higher than 75% in the STFO prepared by this method was established. The O1s (K)-absorption spectra point to increase in oxygen vacancy concentration with increasing Fe content. The lowest degree of structure distortions with enough high oxygen vacancy concentration was traced in STFO (x=0.25 to x=0.35) produced by modified Pechini synthesis, which makes it mostly appropriate for technical applications, e.g., as gas sensors, oxygen separation membranes or as fuel cell material.

Fe doped Ni-Mn-Co-O ceramics with varying Fe content as negative temperature coefficient sensors

Abstract Fe-doped Ni-Mn-Co-O (FNMC) ceramics with the formula, (Fe x Ni 0.3 Co 0.9 Mn 1.8−x , x=0.1, 0.3, 0.5, and 0.7)O 4 were synthesized using a spray drying process. Effect of Fe content on the phase evolution of FNMC compound during heat treatment was studied using X-ray diffraction. A single phase cubic spinel structure with improved crystallinity was observed when the Fe content increased over 0.5. Fe, Ni, Mn and Co ions were homogeneously distributed in the sintered the FNMC ceramics, implying no phase separation occurred during sintering. The valence state of each element was analyzed using X-ray photoelectron spectroscopy, which revealed that Ni, Co, and Fe might have a single valence state while Mn had mixed valence states in the FNMC spinel compounds. The temperature-dependent electrical resistance for the FNMC ceramics was measured. Room temperature resistance and the B-value substantially increased for the FNMC samples with Fe content higher than 0.5. The electrical properties of FNMC compounds can be optimized by controlling the Fe content, which is directly indicative of their potential role as negative temperature coefficient sensors.

A novel heterogeneous Fenton photocatalyst prepared using waste wool fiber combined with Fe3+ ions for dye degradation

Wool fiber Fe complex (Fe-Wool) was prepared with waste wool fiber and Fe3+ ions by a simple exhaust method, and characterized using SEM, FTIR, XRD, XPS, and diffuse reflectance UV-vis spectroscopy. The activity of Fe-Wool was tested as a novel heterogeneous Fenton catalyst for dye degradation in a wide pH range. Effect of Fe content, incorporation of Cu2+ ions, and light irradiation on its catalytic activity was also examined. The results indicated that amino and carboxylic groups or disulfide crosslinks from wool fiber as the ligand sites could react with Fe3+ ions to form Fe-Wool, and the Fe content in Fe-Wool was highly dependent on Fe3+ initial concentration and temperature. Fe-Wool showed a better catalytic activity on the dye degradation under light irradiation than in the dark because it was activated in the UV and visible regions. Incorporation of Cu2+ ions could significantly increase catalytic activity of Fe-Wool for the dye degradation, especially in neutral and alkaline pH range.

The Effect of Fe Content on Semi-solid Microstructures of Al-Mg-Si Based Alloys Produced by Deformation-Semi-Solid-Forming Process

The Effect of Fe Content on Semi-solid Microstructures of Al-Mg-Si Based Alloys Produced by Deformation-Semi-Solid-Forming Process

Effect of Fe content on microstructure and mechanical properties of Cu–Fe-based composite coatings by laser induction hybrid rapid cladding

To select the proper composition and obtain an overall material–microstructure–property relationship for Cu–Fe alloy, the effect of Fe content on microstructure and properties of Cu–Fe-based composite coatings by laser induction hybrid rapid cladding was investigated. Microstructure characterization of the composite coatings was tested utilizing SEM, XRD and EDS. Microhardness measurement was executed to evaluate the mechanical properties of the composite coatings. The results show that for low Fe content, the composite coating presents a feature that Fe-rich equiaxed dendrites are embedded in the Cu-rich matrix. With increasing Fe content, the Fe-rich particles are dispersed in the Cu-rich matrix. With further increasing Fe content, large amounts of Cu-rich particles are homogeneously dispersed in the interdendrite of the Fe-rich matrix. Correspondingly, the average microhardness of the composite coatings increases gradually with the increase of Fe content and the microhardness of Cu14.5Fe83Si2C0.5 coating is much twice higher than that of the substrate.

Fe content dependence of magnetic properties and bending ductility of FeSiBPC amorphous alloy ribbons

Effects of Fe content on magnetic properties and bending ductility of FeSiBPC amorphous alloy ribbons before and after annealing were systematically investigated. It was found that all alloys had high amorphous forming ability and good soft magnetic properties after annealing. The transition temperature of bending ductility-brittleness decreases much faster than that of soft magnetic properties with the increase of Fe content. It is interesting that alloys with Fe content higher than 80 at.% exhibit good ductility before and after annealing at the optimal condition. The alloy with Fe content of 71 at.% is brittle even at as-spun state. The saturation flux density (Bs) and coercivity (Hc) decrease with decrease of the Fe content and deviate from a linear fitting tendency. The temperature asynchronism between magnetic properties and bending ductility of amorphous alloy ribbons was discussed. This work will bring a new perspective to study the annealing induced brittleness and a guidance for the future development of the amorphous alloys.

Effect of Fe on Microstructure and Properties of 8xxx Aluminum Conductor Alloys

The effect of Fe contents (0.3-0.7 wt.%) on the microstructure, electrical conductivity, mechanical and creep properties of 8xxx aluminum conductor alloys was investigated. Results revealed that the as-cast microstructure of 8xxx alloys was consisted of equiaxed α-Al grains and secondary Fe-rich intermetallics distributed in the interdendritic region. The extruded microstructure showed partially recrystallized structure for 0.3% Fe alloy but only dynamically recovered structures for 0.5 and 0.7% Fe alloys. With increasing Fe contents, the ultimate tensile strength and yield strength were remarkably improved, while the electrical conductivity was slightly decreased. Moreover, the creep resistance was greatly improved, which is attributed to the larger volume fraction of fine intermetallic particles and smaller subgrain size in the higher Fe-containing alloys. The creep threshold stress was found to increase from 24.6 to 33.9 MPa with increasing Fe contents from 0.3 to 0.7%, respectively. The true stress exponent values were close to 3 for all three experimental alloys, indicating that the creep mechanism of 8xxx alloys was controlled by dislocation glide.

Mg-Zn-Ca amorphous alloys for application as temporary implant: Effect of Zn content on the mechanical and corrosion properties

In this paper, two Mg-Zn-Ca amorphous alloys were processed and their mechanical and corrosion properties were evaluated and compared. The first alloy was a new composition, Zn-rich, Mg60Zn34Ca6, designed thanks to a multifold approach involving two different criteria, topological instability, and electronic criteria. The second alloy, with less Zn content, was a well-known Mg73Zn23Ca4, used for the sake of comparison. Three kinds of rapidly solidified samples were processed for each composition: ribbons, wedge, and cylindrical samples. The new composition showed much better glass-forming ability and superior corrosion and mechanical properties than the Zn-poorer composition. The effect of Fe content, a typical contaminant in Mg-based alloys, was also evaluated. Electrochemical results in amorphous and in crystalline samples showed that increasing iron to certain amounts has no influence on the corrosion resistance of the investigated alloys.

Effects of Fe content on the microstructure and properties of CuNi10FeMn1 alloy tubes fabricated by HCCM horizontal continuous casting

Heating-cooling combined mold (HCCM) horizontal continuous casting technology developed by our research group was used to produce high axial columnar-grained CuNi10FeMn1 alloy tubes with different Fe contents. The effects of Fe content (1.08wt%–2.01wt%) on the microstructure, segregation, and flushing corrosion resistance in simulated flowing seawater as well as the mechanical properties of the alloy tubes were investigated. The results show that when the Fe content is increased from 1.08wt% to 2.01wt%, the segregation degree of Ni and Fe elements increases, and the segregation coefficient of Ni and Fe elements falls from 0.92 to 0.70 and from 0.92 to 0.63, respectively. With increasing Fe content, the corrosion rate of the alloy decreases initially and then increases. When the Fe content is 1.83wt%, the corrosion rate approaches the minimum and dense, less-defect corrosion films, which contain rich Ni and Fe elements, form on the surface of the alloy; these films effectively protect the α-matrix and reduce the corrosion rate. When the Fe content is increased from 1.08wt% to 2.01wt%, the tensile strength of the alloy tube increases from 204 MPa to 236 MPa, while the elongation to failure changes slightly about 46%, indicating the excellent workability of the CuNi10FeMn1 alloy tubes.

Effect of Fe content on microstructure and mechanical properties of Al0·5CoCrFexNiTi0.5 high-entropy alloys

In this study, Al0.5CoCrFexNiTi0.5 alloys (where the molar ratio (x) is 0.5, 1.0, 1.5, and 2.0) were synthesized to elucidate the effect of their Fe content on their microstructure and mechanical properties. The results show that both Al0.5CoCrFe0.5NiTi0.5 and Al0.5CoCrFe1.0NiTi0.5 alloys consist of four phases, BCC, FCC, σ, and ordered BCC phases. The number of phases decreases to three for the Al0.5CoCrFe1.5NiTi0.5 and Al0.5CoCrFe2.0NiTi0.5 alloys, both of which consist of the FCC, BCC, and ordered BCC phases. The hardness of the alloys decreases from HV748 to HV399 with increasing Fe content. This result shows that addition of Fe to the alloy inhibits the formation of the σ phase while promoting the formation of the FCC phase, and thus indicates that Fe stabilizes the FCC phase. Al0.5CoCrFe0.5NiTi0.5, Al0.5CoCrFe1.0NiTi0.5, and Al0.5CoCrFe1.5NiTi0.5 alloys have a dendritic structure. However, the microstructure of the Al0.5CoCrFe2.0NiTi0.5 alloy changes into a three-phase eutectic structure. The compressive strength (σmax) of the alloys decreases with increasing Fe content. Accordingly, σmax decreases from 2240 to 1736MPa, and the fracture strain increases from 0.11 to 0.45 as the Fe content increases from 0.5 to 2.0. Both Al0.5CoCrFe1.5NiTi0.5 and Al0.5CoCrFe2.0NiTi0.5 alloys exhibit high strength and high ductility.