Effects of Homogenization Conditions on the Microstructure Evolution of Aluminium Alloy EN AW 8006

Abstract

The industrial production of products, such as foil and aluminium alloy strips, begins with the production of semi-finished products in the form of slabs. These are produced by the continuous casting process, which is quick and does not allow the equilibrium conditions of solidification. Non-homogeneity—such as micro and macro segregation, non-equilibrium phases and microstructural constituents, as well as stresses arising during non-equilibrium solidification—are eliminated by means of homogenization annealing. In this way, a number of technological difficulties in the further processing of semi-finished products can be avoided. The aim of this research was the optimization of the homogenization annealing of the EN AW 8006 alloy. With the Thermo-Calc software, a thermodynamic simulation of equilibrium and non-equilibrium solidification was performed. Differential scanning calorimetry (DSC) was performed on selected samples in as-cast state and after various regimes of homogenization annealing and was used for the simulation of homogenization annealing. Using an optical microscope (OM), a scanning electron microscope (SEM) and an energy dispersion spectrometer (EDS), the microstructure of the samples was examined. Based on the results, it was concluded that homogenization annealing has already taken place after 8 h at 580 °C to the extent, that the material is then suitable for further processing.

Effect of Vacuum Heat Treatment on the Microstructure of a Laser Powder-Bed Fusion-Fabricated NiTa Alloy

“…However, further SAED crystallographic analysis will be required to validate the phase composition of the precipitate. The change in the phase composition is due to microstructure homogenization during high-temperature annealing, which causes the gradual disappearance of the eutectic phase [26]. Subsequently, the saturated solution recrystallizes into two distinct crystal structures, Ni 2 Ta and NiTa.…”

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

“…It is evident that microstructural changes such as transformation of large constituent particles, formation of dispersoids, and precipitation/dissolution of precipitates during homogenisation affect the subsequent extrusion behaviour and microstructural evolution. The development of the microstructure and the effect on the final properties are influenced by both alloy additions and heat treatment parameters [11,12]. In addition, precipitation is also controlled in this way [4].…”

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

“…Homogenization is an important part of the aluminum alloy production process, as certain irregularities or inhomogeneities that occur during non-equilibrium solidification can be removed with suitable homogenization annealing. Defects in the microstructure of alloys can cause problems in further thermomechanical treatments [ 1 , 2 , 3 , 4 , 5 , 6 ]. Homogenization annealing enables the elimination of microsegregations and non-equilibrium eutectics, which, if not removed, can cause the material to rupture during further deformation [ 7 , 8 ].…”