Homogenisation Efficiency Assessed with Microstructure Analysis and Hardness Measurements in the EN AW 2011 Aluminium Alloy

Abstract

When extruding the casted rods from EN AW 2011 aluminium alloys, not only their homogenized structure, but also their extrudable properties were significantly influenced by the hardness of the alloy. In this study, the object of investigations was the EN AW 2011 aluminium alloy, and the effect of homogenisation time on hardness was investigated. First, homogenisation was carried out at 520 °C for different times, imitating industrial conditions. After homogenisation, the samples were analysed by hardness measurements and further characterised by microscopy and image analysis to verify the influence of homogenisation on the resulting microstructural constituents. In addition, non-equilibrium solidification was simulated using the program Thermo-Calc and phase formation during solidification was investigated. The homogenisation process enabled more rounded shape of the Al2Cu eutectic phase, equilibrium formation of the phases, and the precipitation in the matrix, leading to a significant increase in the hardness of the EN AW 2011 aluminium alloy. The experimental data revealed a suitable homogenisation time of 4–6 h at a temperature of 520 °C, enabling optimal extrusion properties.

Carbenes trapping on Aluminum-Magnesium surface implanted with Silicon, Germanium, Tin: Promising of semiconductors by molecular modeling approach

“…Therefore, operated organic compounds as corrosion stoppers were chosen and determined on the basis of their physicochemical characteristics [20,21] and relatively little consideration has been dedicated to the quantitative estimation of the internal and steric influence of these compounds upon their inhibition yield. In other works, it has been studied the interaction between imidazole and the aluminum surface which is often employed in experimental researches [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] .…”

“…Furthermore, the researchers used the DFT approach for calculation of Al-Cu-Mg nanoalloys, which led to stability effects during the addition of specific atom amounts in those alloys [47] . Then, the properties of Li, Al, and Cd-doped Mg alloys using a first-principle calculation to calculate the cohesive energy and its electronic structure were evaluated [22] . The results exhibited that Mg-Al alloy has the lowest cohesive energy and is the most stable alloy [48] .…”

Transformation of the Metastable Al6Fe Intermetallic Phase during Homogenization of a Binary Al-Fe Alloy

“…Iron is mostly used as an alloying element in aluminum foil production [ 9 ]. Aluminum and iron form the equilibrium Al 13 Fe 4 phase, but non-equilibrium solidification of alloys containing iron as an alloying element or impurity can lead to the formation of various metastable intermetallic phases, such as Al 6 Fe, Al m Fe or Al x Fe [ 10 , 11 , 12 ]. By homogenizing the alloys, the transformation of metastable phases into stable Al 13 Fe 4 is achieved.…”

“…The formation and transformation of the Al 6 Fe metastable intermetallic phase into the stable Al 13 Fe 4 intermetallic phase have been studied by different authors and methods [ 10 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. During non-equilibrium solidification of Al-Fe alloys, due to increased cooling rates, many different metastable intermetallic phases can form in addition to the stable Al 13 Fe 4 phase [ 25 ].…”