WORK-HARDENING IN A MEDIUM STRENGTH ALZNMG ALLOY

The effect of the precipitation structure on the work hardening proces s taking place at different temperatures in a medium strength AlZnMg a lloy is investigated. The behaviour of some characteristic properties of the stress-strain curves is analysed on the basis of a new hardenin g law. It is obtained that the work hardening decreases strongly with increasing temperature and it becomes zero at about 200 degrees C, whi ch is a consequence of equal rates of accumulation and annihilation of dislocations around the second phase particles.