بررسي تاثير پارامترهاي عمليات ترمومكانيكي بر قابليت كارپذيري آلياژ آلومينيم 2024

The Effect of Thermomechanical Parameters on the Hot Workability of 2024 Aluminum Alloy

The aim of the present study is to investigate the effects of thermomechanical parameters such as hot deformation temperature and strain rate on the hot workability of 2024 aluminium alloy by using hot compression tests. These tests were conducted on the solutionized specimens with strain rates of 0.001-Is-1 at the temperature range of 350-480°C. By plotting true strain-true stress curves, the amounts of flow stresses were found. For the various conditions, study of these curves confirmed the existance of dynamic recovery phenomenon. The activation energy was found to be between 127-14OKJ/mot, showing that dislocation climb controlled dynamic recovery. Dynamic recrystallization phenomenon was not observed in this work. At temperatures of 350°C and 400°C with strain rate of 0.001 s- l and temperature of 400°C with strain rate of 0.01s- I, flow softening was revealed. This behaviour can be attributed to a precipitation coarsening. Furthermore, it was found that the strain-rate sensivity increases with increasing the deformation temperature.