Effect of heat treatment on microstructure and mechanical properties of Al 2024 matrix composites reinforced with Ni60Nb40 metallic glass particles

Al 2024 matrix composites reinforced with 20 and 40 vol% Ni60Nb40 metallic glass particles were synthesized through powder metallurgy using hot pressing and the effect of heat treatment (solution and artificial aging, T6) on microstructure and mechanical properties was examined. The microstructure of the unreinforced matrix shows the formation of CuAl2 and Al2CuMg precipitates after heat treatment, while the composites show the formation of additional CuNiAl and NbNiAl phases due to the reaction between the matrix and glassy particles. The yield strength is improved by the Ni60Nb40 addition in both as-sintered and heat-treated conditions, whereas the ductility is reduced for the composites with 40 vol% of reinforcement. The microstructural modifications due to the interfacial reactions in heat-treated composites result in a significant strengthening contribution. (C) 2019 Elsevier B.V. All rights reserved.