Papers by Keyword: Al-Fe Alloy

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Authors: Jian Feng Zhang, Qi Xian Ba, Jian Zhong Cui
Abstract: The effect of DC gradient magnetic field and the sectional solidification on the structure of Al-Fe hypoeutectic alloy was investigated. The experiment results showed that the morphology and structure of the sample were homogenous, when it was bulk solidified without magnetic field. When the sample was sectionally solidified without magnetic field, the upper part had less iron content, bigger dendritic trunk and less interdendritic precipitate. When the sample was sectionally solidified in the gradient magnetic field, the above-mentioned differences between the upper and lower part were more prominent. The physical essence of the experiments was analyzed with quantum mechanics and solidification theory.
Authors: Pedro R. Goulart, J.E. Spinelli, F. Bertelli, Wislei R.R. Osório, Noé Cheung, Amauri Garcia
Abstract: Upward directional transient solidification experiments have been carried out with an Al-1.0wt%Fe alloy. Tensile tests were carried out with samples collected along the casting length and these results have been correlated with measured cell spacings, since cellular growth has prevailed along the directionally solidified casting. The resulting mechanical properties include ultimate tensile strength, yield tensile strength and elongation. The used casting assembly was designed in such a way that the heat was extracted only through the water-cooled system at bottom of the casting. During non-equilibrium solidification, typical of DC (direct chill) castings, different cooling rates occur from the casting cooled surface up to the top of the casting, causing the formation of metastable intermetallic phases (AlmFe, Al6Fe, etc) in addition to the stable Al3Fe phase. The extensive presence of plate-like Al3Fe phase in the as-cast structure adversely influences the mechanical properties of Al-Fe alloys, since this morphology is more likely to induce microcracks than the fibrous Al6Fe phase. In order to permit an appropriate characterization of these intermetallic phases, they were extracted from the aluminum-rich matrix by using a dissolution technique. These phases were then investigated by optical microscopy and SEM techniques. It was found that the ultimate tensile strength, the yield strength and the elongation increase with decreasing cell spacing and experimental laws correlating cell spacing and these mechanical properties have been established.
Authors: Tokuteru Uesugi, Yorinobu Takigawa, Kenji Higashi
Abstract: Recently nanocrystalline Al-Fe alloys produced by a vapor quench method have been reported. These alloys are supersaturated solid solution and exhibit high strength with good ductility. It is postulated that the high strength of the Al-Fe alloys could be achieved by both the nano-grained structures and the solid solution strengthening. The contribution to the yield strength due to both the grain size strengthening and the solid solution strengthening were analyzed from the experimental data. Then the contribution to the yield strength due to the solid solution strengthening was estimated from the misfit strain calculated from the first principles in order to compare with analytical results estimated from the experimental data.
Authors: Pi Zhi Zhao, Yan Feng Pan, Jiang Tao, Xiang Jun Shi, Qi Zhang
Abstract: The present study investigated the laser welding performance of Al-Fe aluminum alloy sheets with different contents of intermetallic compounds. Under the same welding parameters, the alloy of higher intermetallic compounds content has wide and deep weld pools with uniform sizes. The alloy of lower intermetallic compounds content has narrow and shallow weld pools with nonuniform sizes. The higher content of intermetallic compounds results in higher laser absorptivity and lower thermal conductivity, and then increases the effective absorbed energy during welding, which is beneficial to the formation of wide and deep weld pools. The distribution uniformity of intermetallic compounds influences the size uniformity of weld pools. In the alloy with lower content of intermetallic compounds, the nonuniform distribution of intermeallic compounds results in the formation of abnormal weld pool, leading to the nonuniform size of the weld pools. In the alloy with higher content of intermetallic compounds, uniform distribution of intermetallic compounds make the size of weld pools more uniform.
Authors: Michał Jabłoński, Tadeusz Knych, Beata Smyrak
Abstract: Eight hypoeutectic aluminium alloys with iron content within the range of 0.07-1.09% by weight, were examined. The structure, the mechanical and electrical properties of wires used for electrical purposes were studied. The batch material for the drawing process was wire rod obtained from the continuous casting and rolling line by Continuus-Properzi method. It has shown a linear relationship between mechanical properties of wire rod, a higher plasticity of wire after drawing process and an increase in thermal resistance of the material with increasing iron content. The findings enable to draw conclusions of basic and application characteristics, pointing to the possibility of using aluminium with higher iron content in the wire drawing process of small diameter and microwires for the production of automotive bundles, accumulator cables and winding wires.
Authors: Won Yong Kim, Jae Sung Park, Mok Soon Kim
Abstract: Mechanical properties of a nano-structured Al-8Fe-2Mo-2V-1Zr alloy produced by spray forming and subsequent hot-extrusion at 420°C were investigated in terms of tensile test as a function of temperature. Warm rolling was adapted as an additional process to expect further refinement in microstructure. Well-defined equiaxed grain structure and finely distributed dispersoids with nano-scale in particle size were observed in the spray formed and hot extruded sample (as-received sample). The average grain size and particle size were measured to 500 nm and 50 nm, respectively. While it was found that warm rolling gives rise to precipitate fine dispersoids less than 10 nm without influencing the grain size of matrix phase, in the temperature range of RT∼150°C, distinguishable changes in ultimate tensile strength were not found between the as-received and warm-rolled samples. At elevated temperatures ranging from 350 to 550°C, warm-rolled sample showed a higher value of elongation than as-received one although similar values of elongation were observed between two samples at temperatures lower than 350°C.
Authors: Felipe Bertelli, Elisangela dos Santos Meza, Debora de Jesus Bezerra, Pedro R. Goulart, Noé Cheung, Amauri Garcia
Abstract: In this work, three water-cooled experimental solidification devices were developed, and experiments were carried out with an Al-1.5wt%Fe alloy. The three experimental setups consist of vertical cylindrical steel molds with each of them having different zones cooled by water. For the inward solidification, a cooled tube is used having its upper and bottom part thermally insulated. For the outward solidification, a cooled tube, forming an inner part, is concentrically placed inside a cylindrical mold, which is thermally insulated from the environment, by using insulating materials. For the upward solidification, the bottom part of the mold is water-cooled and consists of a thin (3 mm) disc of carbon steel, whilst the cylindrical surface is covered with insulating material to avoid lateral heat losses. A numerical solidification model based on the finite difference method is applied for the simulation of the three aforementioned cases of solidification from the chilled surface considering transient heat flow conditions. Experimental thermal readings in the castings have been used for the determination of the transient overall metal/coolant heat transfer coefficient, h, through a numerical-experimental fit of casting thermal profiles based on inverse heat transfer calculations. It was found a significant variation of h as a function of time during solidification in the three cylindrical set-ups experimentally examined, including a remarkable increase in h during the outward solidification. Introduction
Authors: Xiu Fang Bian, Jing Yu Qin, Wei Min Wang, Xiao Gang Qi
Authors: Yi Han, Chun Yan Ban, Shi Jie Guo, Qi Xian Ba, Jian Zhong Cui
Abstract: The aim of this work is to study the effect of a low frequency alternating magnetic field on morphology and distribution of A3F2 in the Al-2.89 wt.% Fe alloy. At the cooling rate of 0.05 °C/s, only Al3Fe phase was observed in the iron-containing intermetallics. It was noteworthy that, compared with the conventional solidification, the primary Al3Fe phase was refined and accumulated towards the center of the sample by applying the alternating magnetic field. This phenomenon is considered as the result of the larger Lorentz force acting on the Al3Fe phase than the Al matrix.
Authors: Harushige Tsubakino, Atsushi Yamamoto, Takeshi Kato, Akira Suehiro
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