تحولات زیر ساختاری آلیاژ Ti-6AL-4V در حین تغییر شکل گرم
نویسنده
چکیده
کلیدواژهها
عنوان مقاله [English]
Microstructural Evaluation of Ti-6AL-4V Alloy during Hot Deformation
نویسنده [English]
- K. Farmanesh and A. Najafi-Zadeh
Among the titanium alloys, Ti-6Al-4V is the most widely used. In the present work, the uniaxial hot compressive behavior of Ti-6Al-4V has been investigated under constant strain rates. A series of dilatometery experiments were carried out to determine the transformation temperatures at different cooling rates. Specimens were homogenized at 1050 °C for 10 minutes followed by fast cooling to different straining temperatures from 1050 to 850°C. The cooling rate was chosen fast enough to prevent high temperature transformation during cooling. A series of isothermal compression tests were conducted at different temperatures of 850, 900, 950, 1000, 1050°C at constant true strain rates of 0.1, 0.01 and 0.001 s-1, respectively. Samples were uniaxialy compressed to a true strain of 0.55 followed by water quenching to room temperature. The apparent activation energy for compression in two phase regions was calculated at 840 KJmol-1. The partial globularization of a-phase was observed in the specimens deformed at low strain rates and at temperatures near the transformation zone followed by annealing.
کلیدواژهها [English]
- Thermomechanical processing
- Isothermal hot deformation
- Ti-6Al-4V alloy
- Dilatometery
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