Details

Autor(en) / Beteiligte

• Bai, Z.C.
• Ding, X.F.
• Hu, Q.
• Yang, M.
• Fan, Z.T.
• Liu, X.W.

Titel

Unique deformation behavior and microstructure evolution in high-temperature processing of a low-density TiAlVNb2 refractory high-entropy alloy

Ist Teil von

• Journal of alloys and compounds, 2021-12, Vol.885, p.160962, Article 160962

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •Hot deformation behavior of a low-density refractory high-entropy alloy was studied.•The apparent activation energy for hot-deformation was 401–375 kJ∙mol−1.•A combined DDRX+CDRX process takes place in this novel alloy in hot deformation. Thermal deformation behaviors and microstructure evolution of a novel light refractory high-entropy alloy (RHEA) TiAlVNb2 were investigated in detail. Uniaxial compression was implemented at different strain rates from 10−3s−1 to 10−1s−1 and various temperatures from 1000 °C to 1200 °C. Stress-strain curves combined with electron back scattered diffraction analysis indicate that work hardening, dynamic recrystallization (DRX) and dynamic recovery (DRV) occur during the thermal compression. Flow stress analysis carried out by the Arrhenius-type power law relationship suggests a high apparent activation energy of 401–375 kJ∙mol−1 over the whole range of strain. The DRX acts as one of the main softening mechanisms, in which the DRX grains show a typical trend of increased size and fraction with increased temperature or/and decreased strain rate. Further analyses, however, reveal a unique DRX feature that both discontinuous and continuous DRX processes take place in this RHEA. The discontinuous DRX was proved by bulge (migration) of original grain boundaries, kernel average misorientation map and transmission electron microscopy; while the cumulative misorientation (point to origin) and the new grains formed at original grain interior support the existence of continuous DRX (CDRX).