Towards the Understanding of the Deformation Mechanisms of Refractory Complex Concentrated Alloys Exhibiting B2-Type Order
Abstract
During the period from September 2020 to September 2021, we have investigated and reported the analysis of the deformation mechanisms at 600 deg C in a two-phase, BCC+B2, refractory complex concentrated alloy (RCCA) Al0.5NbTa0.8Ti1.5V0.2Zr. After annealing at 1200 deg C during 2h and subsequent water quenching, the alloy microstructure is unstable and dynamic coarsening of B2 precipitates is evidenced during the mechanical testing at 600 deg C. After true plastic strain of 0.030 at strain rate of 10^-4 s^-1, the deformation becomes highly localized in wavy bands reflecting the profusion of cross-slip. Scanning transmission electron microscopy (STEM) observations highlight the presence of paired a/2<111> dislocations that shear the B2 precipitates in a cooperative process. In addition, some chemical segregation effect is observed along the narrow dislocation bands likely induced to decrease the antiphase boundary (APB) energy of the system. The analysis of the microstructure formed after an annealing at 600 deg C during 120h shows that the presence of discrete intermetallic particles in a disordered BCC matrix. These precipitates consist of semi-coherent B2 phase and also related ordered omega ones. After compressive testing at 600 deg C, the STEM observations reveal that plasticity occur by dislocation glide in the confined regions of the BCC matrix. No shearing events of the precipitates (B2 or omega phases) have been evidenced during the deformation at 600 deg C.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 27, 2022
- Accession Number
- AD1230462
Entities
People
- Michael Mills
Organizations
- Ohio State University