Masoud Hasanpour - Master student of Metal forming, School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran
Abbas Zarei-Hanzaki - Full Professor, School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran

In the current study, two distinct microstructures with different grain size and dislocation distribution wereobtained through rolling to total reduction of 60% at temperatures of 800 and 1000 ℃. The results indicatethat the deformed matrix was maintained at 800 and this leads to banded-like accumulation ofdislocations. Therefore the initial microstructure provides many potential nucleation sites for HCP εformation. This was justified considering the higher values of room temperature strength and ductility forthe material rolled at 800 ℃. In contrast, in the material rolled at 1000 the uniform and nearly equiaxeddislocation distribution were obtained which was ascribed to multiple slip occurred within recrystallizedgrains. This can leads to long distances regions within the grains which was free of geometrically necessarydislocations. Therefore, there are long orientation gradients regions which HCP formation was stopped orpostponed during tensile loading at room temperature.

high entropy alloys, geometrically necessary dislocations, mechanical properties, transformation induced plasticity