Fe Element Content Research Articles

Organic pollutants removal performance and enhanced mechanism investigation of surface‐modified steel slag particle electrode

Steel slag particle electrode was surface modified by metals to improve their catalytic activity. The modification metals were selected by a group of Rhodamine B (RhB) degradation experiment, Mn was proved to be the most appropriate metal for surface modification among three metals. Mn was loaded on the particles via an ultrasound impregnation‐calcination process. The resulting samples were utilized in a three‐dimensional electrode system for RhB degradation. RhB removing influence factors and reaction kinetics were investigated, result showed that the best condition for RhB degradation is: 5 V applied voltage, 15 g dosage of particle electrode, 0.15 mol/L electrolyte concentration, 5 mg/L initial RhB concentration, and pH value 6. The change of the content of Fe element was also monitored by X‐ray photoelectron spectroscopy. The adminicular evidence for the occurrence of electro‐Fenton was displayed and the enhanced mechanism was proposed. © 2018 American Institute of Chemical Engineers Environ Prog, 38: S7–S14, 2019

High purity Fe3O4 from Local Iron Sand Extraction

Indonesia has a long coastline and is rich with iron sand. The iron sand is generally rich in various elements such as iron and titanium. One of the products processing of the iron sand mineral is iron (II) (III) oxide (magnetite Fe3O4). The stages of purification process to extracting magnetite phase and discarding the other phases has been performed. Magnetite phase analysis of ironsand extraction retrieved from Indonesia have been investigated. The result of analysis element of iron sand shows that it consists of majority Fe around 65 wt%. However, there are still 17 impurities such as Ti, Al, Ce, Co, Cr, Eu, La, Mg, Mn, Na, Sc, Sm, Th, V, Yb, and Zn. After extraction process, Fe element content increases up to 94%. The iron sand powder after milling for 10 hours and separating using a magnetic separator, the iron sand powders are dissolved in acid chloride solution to form a solution of iron chloride, and this solution is sprinkled with sodium hydroxide to obtain fine powders of Fe3O4. The fine powders which formed were washed with de-mineralization water. The X-ray diffraction pattern shows that the fine powders have a single phase of Fe3O4. The analysis result shows that the sample has the chemical formula: Fe3O4 with a cubic crystal system, space group: Fd-3m and lattice parameters: a = b = c = 8.3681 (1) Å, α = β = γ = 90°. The microstructure analysis shows that the particle of Fe3O4 homogeneously shaped like spherical. The magnetic properties using vibrating sample magnetometer shows that Fe3O4 obtained have ferromagnetic behavior with soft magnetic characteristics. We concluded that this purification of iron sand had been successfully performed to obtain fine powders of Fe3O4 with high purity.

Influence of dilution rate on the microstructure and properties of FeCrCoNi high-entropy alloy coating

The influence of laser parameters and alloying elements on the dilution rate of FeCoCrNi coating was investigated. It was found that the alloying elements have more significant effect on the dilution rate than the laser cladding parameters. Optical microscopy, scanning electron microscopy, X-ray diffraction analysis, micro-hardness test, wear test, electrochemical corrosion test, and high-temperature oxidation test were conducted to study the influence of dilution rate on the microstructure and properties of the FexCoCrNi coatings. The results have shown that the transfer of Fe element from the substrate could make the mixed entropy of the Fe0CoCrNi coating close to the theoretical mixed entropy of the FeCoCrNi high-entropy alloy. Excess Fe element in the original powder increased the dilution rate, leading to a reduction in the mixed entropy of the coating. However, it did not lead to the generation of new phases in the coating. The atomic radius differences between the elements could lead to large lattice distortion in the FCC crystal lattice. The level of lattice distortion and micro-hardness of the FexCoCrNi coatings increased with increasing Fe element content. Furthermore, the excess Fe elements weakened the self-passivation ability and deteriorated the high-temperature oxidation resistance of the coating.

Influence of Fe Addition on Phase Transformation, Microstructure and Mechanical Property of Equiatomic NiTi Shape Memory Alloy

Based on equiatomic nickel and titanium, three kinds of NiTiFe alloys with a nominal chemical composition of Ni49Ti49Fe2, Ni48Ti48Fe4 and Ni47Ti47Fe6 (at.%), respectively, have been designed to investigate the influence of the addition of Fe element on phase transformation, microstructure and mechanical property of equiatomic NiTi shape memory alloy. The microstructures of three kinds of NiTiFe alloys are characterized by the equiaxed grains instead of the dendrites. Consequently, some Ti2Ni precipitates are found to distribute in the grains interior and at the grain boundaries. The content of Fe element has an important influence on mechanical property of NiTiFe alloy. With increasing content of Fe element, the strength of NiTiFe alloy increases substantially, but the plasticity decreases sharply. It can be concluded that precipitation strengthening and solution strengthening play a significant role in enhancing the strength of NiTiFe alloy. In the case of three NiTiFe alloys, neither martensitic transformation nor reverse transformation can be observed in the range from −150 to 150 °C. On the one hand, the phase transformation temperature is probably out of the scope of the present experimental temperature. On the other hand, the addition of Fe element probably suppresses first-order martensitic transformation or reverse transformation, and consequently the second-order-like phase transformation from an incommensurate stage to a commensurate stage can probably take place.

Tunable Magnetic Properties in CuCr2−x Fe x O4 Ceramics by Doping of Fe

CuCr2−xFexO4 ceramics have been successfully synthesized using the sol–gel method for the first time. With pure formation, material structure has been characterized by x-ray diffraction. The samples have been identified as having the spinel structure with formulae CuCr2−xFexO4. Micrographs obtained by scanning electron microscopy show the dense microstructure of the samples. The stoichiometric ratio of the ceramics has been measured through energy dispersive spectra. Magnetic properties of CuCr2−xFexO4 ceramics have been discussed. Temperature dependence of magnetization presents the gradually increasing irreversible temperature as the content of Fe element increases from x = 0 to 1. Coercive field (HC), remanent magnetization (Mr), and saturation magnetization (MS) respectively display the monotonous variation phenomena with increasing content of Fe. The increasing Mr, MS and the decreasing HC can be attributed to the change of magnetic exchange interaction because of the doped Fe. It also proves that the magnetic properties of CuCr2−xFexO4 ceramics can be effectively tuned by the doping content of Fe.

Effects of Fe Content on Microstructures and Properties of AlCoCrFe x Ni High-Entropy Alloys

The influences of added Fe element on the microstructures and properties of AlCoCrFexNi high-entropy alloys (x denoted the atomic fraction of Fe element at 0.2, 0.4, 0.6, 0.8, 1.2, 1.4, 1.6, 1.8, and 2.0) were investigated. When x = 0.2, the alloy exhibited dendrites morphology, but as the Fe content increased, the AlCoCrFexNi HEAs transformed to equiaxed grains morphology. Inside the equiaxed grains and dendritic grains, spinoidal decomposition microstructure could be clearly observed. The microstructures changed from Cr3Ni2 + B2 + BCC structures to B2 + BCC mixed structures as x exceeded 0.6, the hardness declined from HV637.2 to HV460.2, and the compressive fracture strength showed a slight decrease, whereas the plastic property showed a distinct improvement with the addition of Fe element. The maximum compression strength was 2335MPa when x = 0.2, and the maximum compression ratio was 36% when x = 2.0. The alloys transformed from paramagnetic to ferromagnetic as the content of Fe element increased, and all of the alloys exhibited soft magnetic behaviors.

Preparation of carbon encapsulated iron nanoparticles with very thin shells by DC arc discharge

Carbon encapsulated iron nanoparticles (CEINPs) with very thin shells and good core-shell structures were prepared by DC arc discharge at argon intake temperature (AIT) of 800 °C. The results of high resolution transmission electron microscope (HRTEM), energy dispersive X-ray (EDX) spectroscope, X-ray diffraction (XRD), and X-ray photoelectron spectroscope (XPS) characterizations on the product B show that the thickness of the carbon shells of CEINPs in the product B is in the range of ca. 0.5–5.3 nm, i. e., which can be as thin as only two layers of graphite. The average diameter of the CEINPs is about 24.7 nm. The total content of Fe element in the product B is 77.0 wt%. The saturation magnetization (M s) and coercivity (H c) of the product B are 107.4 emu/g and 143 Oe, respectively. The formation of the CEINPs in the product B is discussed briefly.

Determination of Iron Element in Comb Mushroom by ICP-AES

Iron is indispensable to make hemoglobin and other iron material elements, is also necessary to exchange and oxygen in the blood of an element, many organisms in REDOX system cannot leave it. Most of the iron distribution in special cells in the body. Using the high pressure nitrifying pot method and wet method and treatment of samples were determined in Comb Mushroom samples Fe element content, the determination results are shown in table 2. High pressure nitrifying pot method relative standard deviation of Fe element is 3.689%; Wet method to determine the relative standard deviation of Fe elementt is 5.473%. Visible high pressure nitrifying pot method and treatment of samples of precision of the measuring precision and wet processing samples are relatively good, the measuring precision of the former better. By comparison, high pressure nitrifying pot method specific humidity method to deal with the sample good measuring precision, higher accuracy, and the measurement process to save time.

Effects of vacuum degree on tribological behavior of TiB 2/Al composites

The effects of vacuum degree on the tribological behavior of TiB 2/Al composites were investigated by a pin-on-disc tribometer under five vacuum degrees of 0.01, 0.03, 0.05, 0.07 and 0.1 MPa, respectively. The results show that the friction coefficient decreases with the increase of vacuum degree, while the wear rates change little. EDS spectra of composites wear surfaces show that Fe element content decreases with the increase of vacuum, which is consistent with the change of friction coefficients.

Characteristics Before and After Heat Treatment of Co-Free AB<sub>3</sub>-Type Fe Substituted Hydrogen Storage Alloys Used for Ni-MH Batteries

In this paper, a series of hydrogen storage Co-free AB3-type alloys were directly synthesized with vacuum mid-frequency melting method, and melted alloys were treated by low temperature-short time heat annealing. XRD results indicate that the main phase of melted La0.7Mg0.3Ni3-xFex (x=0.0~0.4) alloys are LaMg2Ni9 and LaNi5 phase. After heat treatment, some LaMg2Ni9 phase transferred into LaNi3 phase because of the loss of Mg during the heat proceeding. The content of Fe element affects phase structure of alloys and led to different electrochemical properties. Heat treatment has positive effects on cycle stability of La0.7Mg0.3Ni3-xFex (x=0.0~0.4) alloys but could cause little reduction of discharge capacity of Fe substituted alloy. However, the discharge capacity of La0.7Mg0.3Ni2.8Fe0.2 alloy increased after heat treatment. The EIS results show that heat treatment has positive effect on H transfer within alloy, and Fe content is related to the diffusion coefficient of H atoms within alloys.

Microstructure- and property-controllable NdAlNiCuFe alloys by varying Fe content

We report the formation of microstructure- and property-controllable Nd60Al10Ni10Cu20−xFex (0 ≤ x ≤ 20) alloys by varying the content of Fe element. The microstructure of the Nd-based alloy can be changed progressively from a full glassy state into a composite state with nanocrystalline particles in the glassy matrix and, finally, into a nanostructured state, accompanied by variation in magnetic property gradually from paramagnetic to hard magnetic. The role of Fe addition in the control of microstructure and magnetic property is clarified. We expect that the results would have implication in the development of the microstructure- and property-controllable functional materials for various applications.

Condensation formation of Co–Fe nanoparticles and the related magnetic properties

Amorphous Co nanoparticles were synthesized by hybrid of induction and laser heating with help of the plasma in vapor. Since Fe–Co alloys were evaporated at low rate without the plasma, the produced Co–Fe nanopartcles are in crystal structure. The coercivity of the nanoparticles decreases with increasing the content of Fe elements.