Processing and properties of nanocrystalline CuNiCoZnAlTi high entropy alloys by mechanical alloying

The present study describes the synthesis of nanocrystalline equiatomic CuNiCoZnAlTi high entropy alloy by mechanical alloying and characterized by XRD, SEM and TEM. The CuNiCoZnAlTi high entropy alloy is mainly composed of BCC solid solution with crystallite size less than 10 nm in as milled condition. The alloy is thermally stable at elevated temperature about 800 degrees C as it retained its nanostructure. This alloy powder was consolidated using vacuum hot press at 800 degrees C with 30 MPa pressure to a density of 99.95%. The hardness and compressive strength of the high entropy alloy are found to be 7.55 and 2.36GPa, respectively. Superior strength of high entropy alloy is attributed to solid solution strengthening and its nanocrystalline nature. (C) 2009 Elsevier B.V. All rights reserved.