DFT – Driven design of hierarchically structured, strong and highly conductive alloys in Cu–Ti system via in situ hydration - re-oxidation

To engineer a Cu–Ti based alloy with titanium-and oxygen-free copper matrix using commercially-feasible powders, an in situ hydrogenation – re-oxidation approach was suggested and supported by grand potential diagram mapping of Cu–Ti–O–H system. Reactive composite powders with nominal composition Cu–10%TiH2, containing 7% native Cu2O, were manufactured by high energy ball milling. The phase and structure formation mechanisms were experimentally investigated by DSC, in situ XRD, SEM, and HRTEM. Multi-stage phase formation mechanism involving decomposition of TiH2, reduction of Cu2O by the released H2, formation of water vapor and re-oxidation of Ti upon cooling leads to the formation of hierarchically-structured copper alloy, reinforced by micron- and nanosized (5–30 nm) Cu3Ti3O precipitates. Due to the metallic nature of Cu3Ti3O and its coherent precipitation from the copper matrix, as well as to the inhibition of Ti dissolution in Cu, the developed alloy demonstrates high yield strength (910 ± 30 MPa) and electrical conductivity (2.6∙107 Sm/m, 42% of International Annealed Copper Standard), comparable to the cold-worked and peak-aged Cu–Be and Cu–Ti bronzes. [Display omitted] •High-throughput DFT calculations and grand potential diagram mapping of the Cu–Ti–O–H system.•Commercially feasible TiH2 and Cu powders (the latter containing native Cu2O oxide) used as the raw materials.•The segregation of Ti and O from Cu matrix and coherent precipitation of Cu3Ti3O inclusions during the sintering.•Strong yet highly-conductive hierarchically-structured Cu–Ti alloys formed as a result.