Fabrication of high strength and high electrical conductivity Cu-Y2O3 composites via laser powder bed fusion

Laser powder bed fusion (LPBF) fabricated oxide dispersion strengthened (ODS) Cu-based composites hold great promise for applications in electronics, nuclear energy, and aerospace. However, the introduction, distribution, and mechanistic effects of oxide dispersoids on the multi-faceted properties of LPBF-prepared ODS Cu still require further investigation and optimization. In this work, 0.5−1.5 wt.% Y 2 O 3 nano-particles were incorporated onto the surface of spherical Cu powders via resonant acoustic mixing (RAM) technology. It was found that the introduction of Y 2 O 3 significantly enhanced laser energy absorption and simultaneously maintained excellent flowability. Additionally, near-fully dense Cu-Y 2 O 3 printed samples were achieved under a lower laser energy density of 677 J/mm 3 . Microstructural analyses indicated a non-linear dependence of the oxide-dispersoid number density on the addition level of Y 2 O 3 , which was attributed to particle agglomeration. The peak value of the number density, reaching 8.8 × 10 20 /m 3 , was observed at 1 wt.% Y 2 O 3 . The resulting high-density, uniformly distributed Y 2 O 3 nano-particles synergistically enhanced the effect of Orowan strengthening, dislocation strengthening and fine-grain strengthening. Consequently, the Cu-1%Y 2 O 3 composite achieved an optimal comprehensive performance, with a tensile strength of 427.3 ± 6.1 MPa, a fracture elongation of 16.6 ± 1.3%, an electrical conductivity of 95.6 ± 0.6% IACS, a softening temperature of 600°C and a high-temperature microhardness (at 500°C) of 90.4 ± 2.9 HV 0.5 . From a broader perspective, the present work offers valuable insights for the further design and optimization of additively manufactured ODS Cu alloys.