Papers by Keyword: Fe Content

Abstract: Cu-based friction materials were prepared by powder metallurgy technology. The effect of Fe content on friction and wear properties of Cu-based friction materials has been investigated. The results indicate that Fe content has great effects on the wear ability of Cu-based friction materials. Fe works as frictional component in copper-based friction materials, influening the mechanical and frictional property of materials. With increasing Fe content, the hardness and friction coefficient of Cu-based friction materials stability increase, the wear rate of the friction materials decreases. When Fe content is 6%, the materials posses stably high friction factors, as well as good wear ability.

Abstract: The microstructures and mechanical properties of T5 heat-treated Al - 5.0 wt % Cu - 0.6 wt % Mn alloys with different Fe content prepared by squeeze casting were studied by tensile test, optical microscopy (OM), scanning electron microscope (SEM) and electron probe micro-analyzer (EPMA). The results showed that the dominate Fe-rich intermetallics are α (CuFe) with a few Al₃(FeMn),Al₆(FeMn), and α-Fe in the alloys depending on different Fe content. With the increasing Fe content continually, the ultimate tensile strength and elongation of the alloys decreased gradually. This is attributed to the increasing amount of Fe-rich intermetallics, the decrease of precipitation particles in α (Al) matrix and the increase of α (Al) dendrite size. The elongation level of 13.7% was still obtained in the squeeze cast alloy even when the Fe content was as high as 1.5%.

Abstract: GH984 is an economic alloy due to the elimination of Co and its containing more than 20% Fe. As a major constituent of GH984 alloy, the Fe reduces the cost, but promotes the precipitation of TCP phase. In order to get an optimum alloy with desired balance among structural stability, mechanical properties and cost, the influence of Fe content on microstructure and mechanical properties of GH984 alloy was investigated in this paper. The results showed that the Fe content had no obvious influence on the major precipitates which were spherical γ′, blocky MC and discrete M₂₃C₆ at grain boundary after standard heat treatment, except the γ/γ ́ misfit. However, during long-term thermal exposure at 750°C, the decrease of the Fe content retarded the precipitation of η phase and enhanced the structural stability. The Fe content had no obvious influence on the tensile strength and ductility. At condition of 700°C/400MPa, the rupture life had not evident change, but the elongation decreased, the fractural model exhibited mix-fracture model and the characteristics of intergranular fracture became obvious with increasing the Fe content. It can be concluded that the decrease of Fe content can improve the structural stability and ductility.

Abstract: The article presents a study of the Fe content influence upon the recrystallization texture and a randomly oriented component in the hot-rolled 3104 alloy flat sheets. With the aid of the X-ray structure analysis of hot-rolled workpieces with various Fe contents, the main textural components have been revealed and the proportion of a randomly oriented component has been found. In order to establish an effect of the specific volume of the recrystallization texture on cold-worked coil anisotropy, the sheet earing tests for all batches were performed.

Abstract: An Ni-Fe alloy on the surface of nickel foam was prepared by electro deposition. The effects of technological parameters including current density, pH value, temperature and the ratio of [Ni²⁺] to [Fe²⁺] of planting solution on the thickness and iron content of the alloy coating were studied. The cross-section microstructure and surface morphologies were observed by optical microscopy and scanning electron microscope, and the compositions of the alloy coating were analyzed by energy dispersive spectrometer and ICP-AES. Experiment results show that the thickness of the alloy coating is increased with increasing current density, temperature, pH value and the ratio of [Ni²⁺] to [Fe²⁺] of the planting solution. The Fe contents of the alloy coating is increased with increasing current density and pH value of the planting solution, and decreased with increasing temperature and the ratio of [Ni²⁺] to [Fe²⁺] of the planting solution. A 36.2 μm thick alloy layer of uniform and dense coating with the Fe content of 60.5 wt% is obtained under the parameters of n(Ni²⁺)/ n(Fe²⁺)= 4, current density = 10 A/dm² and pH = 4.2 at 50 °C for one hour.

Abstract: SrFe_xCo_0.5O_3-δ (x=0.5, 0.75, 1.0, 1.25) powders have been synthesized by the solid state reaction process. The effect of Fe content on the microstructure and properties of the SrFe_xCo_0.5O_3-δ powders were investigated in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermo-gravimetric analysis and differential scanning calorimeters (TGA/DSC). XRD results reveal that the phases of the SrFe_xCo_0.5O_δ powders are dependent on the content of Fe. X-ray diffraction. SEM images show that the obtained powders have similar morphology with particle structure and uniform size distribution. The phase transition from ordered brownmillerite structure to disorder perovskite structure is strongly dependent on the content of Fe by the TGA/DSC analysis of the SrFe_xCo_0.5O_3-δ powders. Phase transition temperature increases from 770°C to 800°C with the x value in the SrFe_xCo_0.5O_3-δ increasing to 1.0. But the phase of the SrFe_1.25Co_0.5O_3-δ powder maintains unchanged behaving good phase stability and chemistry stability.

Abstract: The effect of Fe content on hot tearing of the high-strength Al-Mg-Si alloy was systematically investigated. In this study, a thermodynamic calculation software Thermo-Calc was used to calculate the solidification path under the non-equilibrium condition, and the mechanical properties of this alloy have also been investigated during solidification using an electromagnetic induction heating tensile machine. In order to confirm the calculation results of solidification path, a quenching test also was carried out. By using the Thermo-Calc, the sequence of crystallization, crystallization temperature of formed phases and their crystallized amount were systematically investigated for each alloy in which Fe content was changed. Furthermore, by comparing the fracture surfaces of the tensile testing sample and DC billet, the temperature range of crack initiation of the alloy was examined. Comparing the temperature range of crack initiation with the crystallization phase and its crystallization order, Fe content of high-strength Al-Mg-Si alloy influenced hot tearing significantly owing to the crystallization behavior of α(AlFeMn).