New high-strength aluminum alloy on the basis of secondary materials

Abstract

Six alloys of the Al-Ca-Zn-Mg system with additives of copper, manganese, iron and silicon were studied in order to simulate the composition of an alloy prepared on the basis of secondary aluminum. The alloys were made in the form of ingots with dimensions of 140×200×20 mm that were subjected to subsequent deformation treatment by hot rolling from a thickness of 20 mm to a thickness of 1 mm, and then cold-rolled sheets with a thickness of 0.5 mm were obtained from them. A cylindrical ingot with a diameter of 40 mm and a length of 200 mm was also made. Rods with a diameter of 14 mm were obtained from it by radial displacement rolling. Hot deformation treatment of ingots was carried out at a temperature of 450°C without prior homogenizing annealing. Cast and deformed specimens were examined using optical and scanning electron microscopy. No coarse acicular particles of iron- and silicon-containing phases, as well as any other coarse intermetallides, were found in the microstructure of the specimens. Mechanical tests were carried out using the method of uniaxial tension of deformed semi-finished products that were not subjected to additional strengthening heat treatment. According to the test results, an alloy of optimal composition was selected. The possibility of obtaining products from high-strength and high-tech aluminum-calcium alloy based on secondary raw materials without the use of homogenization and quenching was established.

Keywords

• secondary aluminum
• hot rolling
• radial displacement rolling
• homogenizing annealing
• strengthening heat treatment
• mechanical properties
• microstructure