Microstructure and mechanical properties of Al2O3 dispersion strengthened Cu by laser in-situ aluminum thermal reduction processing

• The Al 2 O 3 dispersion strengthened copper alloy by laser in-situ aluminum thermal reduction processing. • The produced alumina particles are α-Al 2 O 3 particles, and the coherent interface is formed with the copper matrix. • The enhancement of strength is mainly ascribed to the strengthening mechanism induced by the precipitated particles. Laser-assisted in situ aluminothermic reduction process was developed to address nanoparticle dispersion inhomogeneity and grain coarsening in ODS-Cu composites. Using CuO, Al, and Cu powders (Al:CuO = 3:2), ball milling and laser deposition enabled in situ formation of uniformly dispersed α-Al 2 O 3 nanoparticles (59 nm, 1.15–2.77 vol%) with semi-coherent interfaces. The Zener pinning effect refined grains from 5.28 μm to 3.51 μm. At 0.75 wt% Al, optimal tensile strength (90.2 MPa, +16.5 %) and elongation (7.5 %, +19 %) were achieved via synergistic Orowan and Hall–Petch strengthening. Thermal conductivity decreased from 298 to 265 W·m −1 ·K −1 with rising Al 2 O 3 content. Excessive Al caused agglomeration, reducing modulus and inducing premature failure. This method offers a route for fabricating ODS-Cu with balanced strength and thermal performance for fusion reactor applications.