Microstructure and properties of a refractory high-entropy alloy after cold working

A refractory high-entropy alloy HfNbTaTiZr was successfully rolled at room temperature up to 86.4% reduction in thickness (true thickness strain is -2.3). This represents the first successful attempt to cold roll a HEA with a BCC crystal structure. The microstructure and properties of the rolled sheets were determined in the as-rolled condition and after annealing at 800 degrees C, 1000 degrees C, and 1200 degrees C. Cold rolling resulted in extensive grain elongation, formation of deformation bands within the grains, and development of crystallographic textures that depended on the rolling reduction. The 86.4% cold-rolled sheet had true tensile stress of 1295 MPa and tensile ductility of 4.7%. After annealing at 1000 degrees C and 1200 degrees C, complete recrystallization of the cold-rolled sheet occurred. After annealing at 1000 degrees C, the true tensile stress and ductility of the sheet were 1262 MPa and 9.7%, respectively. (C) 2015 Elsevier B.V. All rights reserved.