Features of decomposition of a solid solution of high-strength casting aluminum alloy subject to plastic deformation

To improve the complex of mechanical properties of aluminum alloys, it is possible to use deformation and heat treatment. Increase in strength characteristics with increasing ductility and impact toughness is ensured by high-temperature thermomechanical treatment. The possibility of implementing thermomechanical treatment of cast aluminum alloys has been studied. To estimate hardenability, which is the most important characteristic of high-strength cast aluminum alloy, a diagram of isothermal decomposition of a supersaturated solid solution has been constructed. The curves of decomposition of the solid solution are given for undeformed and deformed cast alloy with an optimal degree of deformation of 30 %. The onset of decomposition of the supersaturated solid solution was recorded by a decrease in strength characteristics compared to the level of properties of the quenched and aged alloy. It has been established that when implementing HTMT, hot plastic deformation, carried out at the homogenization temperature, intensifies the decomposition of the supersaturated solid solution of high-strength cast aluminum alloys during subsequent cooling and reduces hardenability.