Affiliation:
1. Laboratory of High-Entropy Alloys, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China
Abstract
The NbTaHfTiZrV0.5 is a refractory multi-principal-element alloy with high strength and good ductility at room temperature. It is important for possible high-temperature applications to investigate the deformation mechanism of the NbTaHfTiZrV0.5 alloy at different temperatures using tensile tests. In this investigation, the tensile tests were conducted at room temperature to 1273 K on sheet materials fabricated by cold rolling combined with annealing treatments. At 473 K, the NbTaHfTiZrV0.5 alloy exhibited a high tensile ductility (12%). At a testing temperature range of 673~873 K, the ductility was reduced, but the yield strength remained above 800 MPa, which is rare in most other alloys. The TEM investigations revealed that a dislocation slip controlled the plastic deformation, and the degree of deformation was closely related to the dislocation density. The true stress–strain curves of the alloy under different deformation conditions were obtained by tensile deformation at different deformation temperatures (673~873 K) and strain rates (0.001~0.0005 s−1). Experimental results were utilized to construct the parameters of a constitutive model based on a traditional mathematical model to predict the flow behavior at high temperatures. The excellent high-temperature mechanical properties of the NbTaHfTiZrV0.5 alloy will enable it to be used in several engineering applications.
Funder
the National Key Laboratory for Remanufacturing, Academy of Armored Forces Engineering
the Fundamental Research Program of Shanxi Province, China
the State Key Lab of Advanced Metals and Materials of China
Subject
General Physics and Astronomy