Papers by Keyword: Al-Mg Alloy

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Authors: Miroslav Karlík, Margarita Slámová, Petr Homola, P. Sláma, Miroslav Cieslar
Abstract: Mechanical properties and microstructure of twin-roll cast (TRC) pure aluminium, Al-Fe-Mn-Si (AA8006) and Al-Mg (AA5754) alloy sheets ARB processed at ambient and elevated temperatures (200, 250, 300 and 350°C) were investigated. Processing at elevated temperatures results in better bonding but it produces smaller increases in hardness. AA8006 specimens were processed without any problems up to 7 cycles. The alloy AA5754 suffered from severe edge and notch cracking since the first cycle. The strength was evaluated from tensile test and microhardness measurements; the microstructure was examined using light microscopy, and transmission electron microscopy. The microstructure was compared to that of conventionally cold rolled (CCR) specimens with true strain ε of 0.8, 1.6, 2.4 and 3.2 corresponding to the strain induced by 1 to 4 ARB cycles. The work hardening of alloy AA8006 saturated after the 3rd cycle, whereas the hardness of alloy AA5754 increased steadily up to the 5th cycle. Very fine grain structure with large fraction of high angle boundaries was observed in both alloys after two cycles of ARB. The grains were refined to submicrometre and nanometre size (down to 90 nm in alloy AA5754). Intensive post-dynamic recovery was observed in AA8006 specimens. The recovery is less pronounced in the AA5754 alloy with high concentration of solute atoms in solid solution.
767
Authors: Da Li Cao, Ji Kun Wang, Si Chen Guo, Qin Hong Fang, Zhong Ning Shi
Abstract: The electrochemical formation of Al-Mg master alloys were investigated in NaCl-MgF2-MgO melt at 850°C. The results revealed that cell voltage was nearly constant during electrolysis process, Mg content in Al-Mg master alloys increased with increasing of electrolysis time when Mg content was less 7.03mass%, Mg content in Al-Mg master alloys can be up to 7.03mass% for 4h electrolysis. The results of XRD indicated that phase structure of the Al-7.03Mg mass% alloy existed single phase α-Al, MgCl2 and NaMgF3 in electrolyte were observed after electrolysis. And the formation mechanism of Al-Mg master alloy was discussed as well.
260
Authors: Fahrettin Ozturk, Mehmet A. Arslan
Abstract: In this study, a temperature distribution of 5083-O aluminum-magnesium (Al-Mg) alloy is analyzed at various die and blank initial temperature conditions using finite element analysis approach. Temperature distribution results of the blank reveal that the dies must be heated to predetermined temperatures for successful warm forming, even the blank is kept at room temperature.
329
Authors: Wei Gong, Zhou Hua Jiang, Dong Ping Zhan
Abstract: There is less study about the effect of magnesium on characteristics of bearing. In the paper, the bearing steel was modified by three types of Al-Mg alloys. Firstly, the total oxygen content value was measured, and then the inclusion size, shape and chemical composition were analyzed by optical microscopy, SEM and EDX. The results show that, after treated by Al-Mg alloy, the total oxygen content descends remarkably and the alumina inclusion with big size and different shapes transform into spinel with small size and spherical shape. The optimal effect of inclusion modification is acquired after treated by NO. 3 Al-Mg alloy containing 16.55 wt% Mg, most of the inclusions in steel are spinel and magnesia, and the size of 96.23 wt% inclusions is less than 3μm.
387
Authors: Hiroyuki Hosokawa, Hajime Iwasaki, Mamoru Mabuchi, Kenji Higashi
655
Authors: Takashi Mizuguchi, Tsutomu Ito, Kota Kimura, Yasuhiro Tanaka
Abstract: In this study, the high-temperature ductility of a fine-grained, polycrystalline 5083 solid solution alloy was investigated. The composition of the alloy in mass% was Al–4.5 Mg–0.68 Mn–0.19 Fe–0.13 Si–0.11 Cr. Grain refinement was effectively achieved in the stir zone by a friction stir process, and the grain size could be reduced to 3.7 μm. Tensile tests were performed at temperatures ranging from 643 to 743 K and strain rates ranging from 0.001 to 0.1 /s. The stress–strain curves showed that the flow stress continuously decreased until it reached a maximum value of stress and fractured after the initial strain hardening occurred. The value of elongation-to-failure was more than 100% when temperatures were greater than 693 K. The high ductility observed at this point can be referred to as superplastic-like elongation. This phenomenon has been reported in some Al–Mg alloys. The experimentally determined stress exponent (n value) and activation energy for deformation were about 2.5 and 123 kJ/mol, respectively. These results suggest that the grain boundary sliding, accompanied by solute drag motion of dislocations, was a rate controlling process for deformation.
360
Authors: Xun Lei Gu, Yu Qiao Shan, Chang Sheng Liu
Abstract: The Al-Mg coatings were deposited on high-speed electro-galvanizing steel by using double-target DC magnetron sputtering. Numerous Al-Mg coatings were prepared with a range of different Mg-target power at different substrate temperatures. The morphologies and compositions were analyzed by SEM, EDS and XRD, the corrosion-resistance properties with different sputtering parameters were discussed by electrochemical measurement. It was found that with the substrate temperature increasing, the porosity decreased, meanwhile, higher substrate temperature resulted in more granular particles and an increased average particle size, but that did not affect corrosion properties obviously. The corrosion-resistance properties were found to be significantly affected by the targets power. As the power of Al-target and Mg-target were 900W and 200W respectively, the film acted the best corrosion-resistance property. Corrosion current density was approximately 4μA/cm2, decreased significantly compared with galvanized sheet. After analysis, the coating was mainly composed of Al12Mg17 which afforded sacrificial anode protection. As the Mg-target power over high relative to Al-target, the coating was composed of Al12Mg17 and MgZn2, the latter can cause micro-galvanic acceleration of corrosion.
1987
Authors: Jong Won Yoon, E.R. Wallach
Abstract: The CW CO2 laser weldability of various Al-Mg alloys was investigated in terms of weld strength, ductility, Vickers hardness, formability and solidification cracking tendency when both autogenous and wire feed welding were made. Tensile strength of the laser welds was lower than that of the corresponding base metals, and it was linearly proportional to the Mg content of the weld metal. Formability and ductility of Al-Mg alloy laser welds were lower than those of corresponding base alloys as well. As for the weld solidification structure, as the Mg content increased in the weld metal, more equiaxed grains developed. Hence, softening of weld metal and solidification cracking were decreased in the weld metal containing higher Mg. Solidification cracking of Al-Mg alloy laser welds showed the highest susceptibility at 1.6 to 1.9wt.% Mg, and it decreased with further increase of Mg content.
539
Authors: D. Sampath, S. Moldenhauer, H.R. Schipper, K. Mechsner, A. Haszler
1089
Authors: Tomoyuki Fujita, Hisashi Hasegawa, Z. Horita, Terence G. Langdon
1205
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