The Influence of Homogenization Annealing on the Mechanical Properties and Specific Electrical Conductivity of ALTEK Alloys

The influence of homogenization annealing on the structure and properties of aluminum heat-resistant ALTEK alloys is studied. The 2Cu1.5Mn and 3Cu2Mn alloys are homogenized at 450°C (30 h) followed by hot and cold rolling to a thickness of 1 mm and heat treatment at 300–500°C (3 h). It is found that homogenization annealing allows achieving higher specific electrical conductivity (SEC) compared to non-homogenized alloys owing to the earlier onset of decomposition of the aluminum solid solution. However, a decrease in strength characteristics is observed: after annealing at 300°C, the tensile strength decreases to 25%, while non-homogenized alloys demonstrate higher thermal stability—their strength decreases by 3% compared to the cold-rolled state. This phenomenon is most likely due to the fact that homogenization promotes the growth of Al20Cu2Mn3 particles, which makes the latter less effective in inhibiting the processes of recovery and recrystallization. For the 2Cu1.5Mn and 3Cu2Mn alloys, after annealing at 400°C (3 h), the following properties are obtained: tensile strength is 215 and 201 MPa, conditional yield strength is 79 and 81 MPa, relative elongation is 16.4 and 19.2%, and SEC is 27.7 and 28.6 MS/m.