Study on inhomogeneous characteristics and optimize homogenization treatment parameter for large size DC ingots of Al–Zn–Mg–Cu alloys

Influence of Homogenization on Microstructural Response and Mechanical Property of Al-Cu-Mn Alloy

“…High cooling rate, complex and high content of alloying elements, and non-equilibrium solidification conditions in direct chill (DC) casting inevitably cause severe segregation and the formation of non-equilibrium eutectics and intermetallics [ 21 ]. The Cu, Mn, and other alloying elements usually form the uneven distribution of low-melting-point brittle non-equilibrium eutectic compounds or other undissolved intermetallics at the grain boundary, which was proposed by Gao et al [ 22 ].…”

“…The 2219 alloy ingots had severe microsegregation and the average grain size was about 40–80 μm. There was a large amount of continuous non-equilibrium solidification eutectic elongated along the grain boundaries and at interdendritic regions, which inevitably have negative effects on the strength and toughness of the alloy and produce some negative impacts on the processability and applicability [ 21 ]. Different types of eutectic phases are indicated by the arrows in Figure 4 b.…”

“…Evidently, the homogenization procedure encouraged numerous brittle eutectic phases to effectively dissolve into the matrix, reducing the probability of brittle fracture along grain boundaries and improving the strength of the material. Meanwhile, solid solution strengthening can be achieved by non-equilibrium solution [ 21 , 25 ], and thereby it was beneficial to obtain aging strengthening through precipitated phases precipitating from the matrix during the subsequent aging process. Besides, the distinct microstructural changes during ring rolling, which were characterized by high density dislocations ( Figure 10 b) and fine sub-grains with relatively low misorientations ( Figure 11 d) were responsible for the increase of tensile strength, as reported previously [ 28 , 33 ].…”

Microstructure, mechanical properties and stress corrosion cracking of Al–Zn–Mg–Zr alloy sheet with trace amount of Sc

“…EDX analysis results in Table 3 reveal that the white phases in point A are close to T-Mg 32 (Al, Zn) 49 in composition, only Al, Zn and Mg elements are detected by EDX at triangular grain boundary area, suggesting that it may be the mixture of α-Al, η-MgZn 2 and T-Mg 32 (Al, Zn) 49 . The grey phases as shown in point B are indissoluble impurity phases containing Fe, Mn and Si elements and they may be the α-Al matrix with solute of elements Zn, Mg, Fe, Si [26][27][28]. The concentration of the M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 6 elements in the alloy decreases from grain boundary to inside.…”

Effect of Cu, Zn, and Mg Concentration on Heat Treating Behavior of Squeeze Cast Al-(10 to 12)Zn-(3.0 to 3.4)Mg-(0.8 to 1)Cu

“…They gain their OPEN ACCESS strength through various precipitates that are obtained through heat treatment. Due to their high alloy content, they are generally considered to have poor cast-ability, suffering from porosity, hot tear defects, poor fluidity and inhomogeneous cast microstructure [1]. As a result, billets of cast Al-Zn-Mg-Cu typically undergo thermomechanical processing to obtain optimal mechanical properties and must be forged or machined to obtain a net shaped part.…”