Hot Deformation and Dynamic Recrystallization Behavior of CoCrNi and (CoCrNi)94Ti3Al3 Medium Entropy Alloys

The CoCrNi and precipitate-hardened (CoCrNi)94Ti3Al3 medium entropy alloys (MEAs) have attracted much attention, due to their exceptional mechanical properties, whereas the hot deformation characteristics have not been revealed. In the present study, we investigated the dynamic recrystallization behavior and microstructure evolutions of the two MEAs hot-compressed at single-phase temperatures. The constitutive equation was obtained, and microstructures were observed. Discontinuous dynamic recrystallization acted as a key mechanism of grain refinement at a relatively higher temperature and lower strain rate, which leads to the formation of a homogeneous grain structure. The addition of Ti and Al promoted dynamic recrystallization due to the solid solution hardening effect. The results provide valuable guidelines for microstructure refinement via thermomechanical processing.

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Flow Behavior and Dynamic Recrystallization of BT25y Titanium Alloy During Hot Deformation

High Temperature Materials and Processes ◽

10.1515/htmp-2016-0100 ◽

2018 ◽

Vol 37 (2) ◽

pp. 181-192 ◽

Cited By ~ 1

Author(s):

Xuemei Yang ◽

Hongzhen Guo ◽

Zekun Yao ◽

Shichong Yuan

Keyword(s):

Dynamic Recrystallization ◽

Hot Deformation ◽

Volume Fraction ◽

Flow Behavior ◽

Strain Rates ◽

Recrystallization Behavior ◽

Lower Strain ◽

Deformation Activation Energy ◽

Strain Data ◽

Dynamic Recrystallization Behavior

AbstractThe high-temperature plastic deformation and dynamic recrystallization behavior of BT25y alloy were investigated within the deformation temperatures of 1,213–1,293 K and strain rates of 0.001–1.0 s–1 on a Gleeble-1500 thermo-mechanical simulator. Results showed that the dynamic recrystallization (DRX) mechanism played an important role in the hot deformation of BT25y alloy. Based on the regression analysis of the true stress–strain data, the stress exponent and deformation activation energy of BT25y alloy were calculated to be 3.4912 and 288.0435 kJ/mol, respectively. The θ-σ and dθ/dσ–σ curves were plotted to further obtain the critical stress and critical strain for the occurrence of DRX. Based on the analysis results, the DRX kinetic model was established. The model was validated by the comparison between predicted and experimental volume fraction of DRX. As the DRX evolution was sensitive to deformation temperature and strain rate, quantities of dynamically recrystallized grains appeared at higher temperatures and lower strain rates.

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Hot Deformation and Dynamic Recrystallization Behavior of Fe-8Mn-6Al-0.2C Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.797 ◽

2017 ◽

Vol 898 ◽

pp. 797-802 ◽

Cited By ~ 1

Author(s):

Xuan Li ◽

Ren Bo Song ◽

Tai Kang ◽

Nai Peng Zhou

Keyword(s):

Dynamic Recrystallization ◽

Strain Rate ◽

Hot Deformation ◽

Peak Strain ◽

Experimental Steel ◽

Softening Mechanism ◽

Lower Strain ◽

Dynamic Recrystallization Behavior ◽

Typical Strain ◽

Higher Temperature

Hot deformation and dynamic recrystallization (DRX) behaviors of Fe-8Mn-6Al-0.2C steel were investigated by means of single-pass compression experiments at temperature ranging from 850 °C to 1150 °C and different strain rate of 0.01~10 s-1. The flow strain curves were analysed and showed that the higher temperature and lower strain rate led to the smaller critical stress, which meant softening mechanism was easier to occur; The constitutive equation of experimental steel was established and the relationship between peak strain and Z parameter was figured out; A hot processing map of experimental steel was developed over a power dissipation map for the typical strain of 0.9, indicating the best region of high workability in the study conditions. DRX was promoted with increase of deformation temperature and decrease of strain rate, and the banded grains had been broken and grew up obviously.

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