Study on Hot Deformation Behavior of TiC Particle-Reinforced Ti Matrix Composites

Abstract:

The hot deformation behaviors of TiC particle-reinforced Ti matrix composites were studied at the temperature range of 900~1150 ℃ and the strain rate range of 0.001~10 s-1 on the Gleeble-1500 simulator by the hot compression test. On the basis of the obtained stress-strain curves, the hot deformation characteristics of the alloys were analyzed; the average deformation activation energy of 799 kJ/mol in the (α+β) region and 105 kJ/mol in the β region were calculated using kinetic rate equation, and the processing map for hot working was established based on the kinetic model. The high-power dissipation region and flow instability region in the processing map were analyzed. The deformation mechanism of different regions in the processing map was determined and the microstructure evolution after deformation was observed and studied. The results show that superplastic deformation and dynamic recrystallization was observed at 900~980 ℃ and 0.001~0.1 s-1; the leading deformation mechanism is dynamic recrystallization which controlled by sub-boundary migration and diffusion at 1000~1100 ℃ and 0.1~10 s-1; and the two flow instability regions appeared at the temperature range of 900~950 ℃ and strain rate range of 0.1~10 s-1 and the temperature range of 1080~1130 ℃ and strain rate range of 0.001~0.01 s-1 according to the processing map.

Key words:TiC particle-reinforced Ti matrix composite; hot deformation; processing map; deformation mechanism