Tunable microstructures and tensile mechanical properties of oxide-dispersion-strengthened Cu by extrusion and secondary processing

In this paper, the influence of extrusion ratio and secondary processing of hot rolling on microstructural features and tensile mechanical properties of samples produced by extrusion of mechanically alloyed Cu-5vol.%Al2O3 alloy powders is investigated. The results show that the extrusion ratio and subsequent rolling greatly affect the sizes of Cu grains and Al2O3 particles, spatial distribution of Al2O3 particles and dislocation density in the prepared bulk Cu-5vol.%Al2O3 alloys. This readily results in the samples prepared by various processing ways displaying different Al2O3 particle size and spatial distributions, Cu grain size distributions as well as dislocation densities. As a result, a total tensile elongation of over 10% and a tensile strength of approximately 600 MPa are attained in an extruded and rolled Cu-5vol.%Al2O3 sample, which are difficult to obtain concurrently in the commercial Al2O3-dispersion-strengthed Cu materials prepared by internal oxidation. To understand these prominent mechanical combinations, we analyze and discuss the different tensile behaviors observed in the fabricated samples on the basis of their specific microstructural characteristics. (C) 2019 Elsevier B.V. All rights reserved.