Evolution of Microstructure and Mechanical Properties of a New Al–Cu–Er Wrought Alloy

• Published in: Physics of metals and metallography Vol. 120; no. 6; pp. 614 - 619
• Main Authors: Pozdnyakov, A. V., Barkov, R. Yu, Sarsenbaev, Zh, Amer, S. M., Prosviryakov, A. S.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.06.2019; Springer Nature B.V
• Subjects: Annealing; Casting alloys; Chemistry and Materials Science; Copper; Deformation; Elongated structure; Evolution; Grain size; High strength alloys; Inclusions; Intermetallic phases; Materials Science; Mechanical properties; Metallic Materials; Microstructure; Recrystallization; Rolling direction; Sheets; Strength and Plasticity; Tensile tests; Thermal stability; Ultimate tensile strength; Wrought alloys; Yield stress; hardness; erbium; microstructure; heat treatment; aluminum alloys; rare-earth metals
• ISSN: 0031-918X; 1555-6190
• DOI: 10.1134/S0031918X19060097

The evolution of the microstructure and mechanical properties of deformed sheets made of a new Al–4Cu–2.7Er alloy has been studied in the course of homogenization and annealing. The structure of the cast alloy consists of a dispersed eutectic ((Al) + Al 8 Cu 4 Er), Al 3 Er-phase inclusions located along the dendritic-cell boundaries, and a nonequilibrium AlCu phase. During annealing at 605°C before quenching, the intermetallic phases have high thermal stability: the particle size of Al 8 Cu 4 Er and Al 3 Er phases does not exceed 1–4 µm. The annealing of deformed sheets at temperatures below 300°C leads to a slight decrease in the hardness; grains elongated along the rolling direction are observed in the structure. With an increase in the annealing temperature from 350 to 550°C, the recrystallized grain size increases from 8 ± 1 to 14.5 ± 1.5 μm. The uniaxial tensile tests showed that the annealed alloy possesses sufficiently high strength characteristics: yield stress of 260–280 MPa, ultimate tensile strength of 291–312 MPa, and relative elongation of 5.5–6.1%.