Effect of Zr additions and annealing temperature on electrical conductivity and hardness of hot rolled Alsheets
(1. Department of Casting Technologies, National Research and Technological University “MISIS”,
Leninsky Prospect 4, Moscow 119049, Russia;
2. UC RUSAL, 13/1, Nikoloyamskaya streat, Moscow 109240, Russia;
3. Brunel University London, BCAST, Kingston Lane, Uxbridge UB8 3PH, UK;
4. Tomsk State University, Tomsk, Prospect Lenina 36, 634050, Russia)
Leninsky Prospect 4, Moscow 119049, Russia;
2. UC RUSAL, 13/1, Nikoloyamskaya streat, Moscow 109240, Russia;
3. Brunel University London, BCAST, Kingston Lane, Uxbridge UB8 3PH, UK;
4. Tomsk State University, Tomsk, Prospect Lenina 36, 634050, Russia)
Abstract: The influence of annealing cycles up to 650 °C on the specific conductivityand hardness (HV) of hot-rolled sheets of Al alloys containing up to 0.5% Zr (mass fraction) was studied. Using analytical calculations of phase composition and experimental methods (scanning electron microscopy, transmission electron microscopy, electron microprobe analysis, etc), it is demonstrated that the conductivity depends on the content of Zr in the Al solid solution which is theminimum afterholding at 450 °C for 3h. On the other hand, the hardness of the alloy is mainly caused by the amount of nanoparticles of the L12 (Al3Zr) phase that defines the retention of strain hardening. It is shown that the best combination of electrical conductivity and hardness values can be reached within an acceptable holding time at the temperature about 450 °C.
Key words: Al-Zr alloys;Al3Zr nano-particles; phase composition; electrical conductivity; annealing temperature