Refractory high entropy alloy TiZrHfNbTa matrix composites reinforced with in-situ nitrides were prepared by vacuum arc melting. The designed composites are composed of BCC matrix and FCC nitride phases, with a particular orientation relationship between them: [111](BCC)parallel to[011](MN),(10 (1) over bar)(BCC)parallel to(200)(MN),(1 (1) over bar0)(BCC)parallel to(1 (1) over bar1)(MN). The composites show enhanced strengths both at room temperature and high temperature compared with the matrix alloy and increase with the increment of N content. The ambient and elevated temperature (1000 degrees C) compressive yield strength is up to 2125 MPa and 350 MPa, respectively, and decent fracture strains (> 19.3%) at room temperature are maintained. The underlying strengthening mechanisms are discussed systematically, and the increase in strength is mainly attributed to the combination of dislocation strengthening, load-transfer effect and Orowan strengthening. (C) 2022 Elsevier B.V. All rights reserved.
Key words
High entropy alloy matrix composites/Microstructures/Mechanical properties/Strengthening mechanisms/CARBIDE
NSTL
Elsevier