The Effect of Reduction Heat Treatment After Mechanical Alloying on the Microstructure and Properties of Cu-Y2O3/W Composites

During the preparation of Cu-Y₂O₃/W composites via the in-situ reaction method, the introduction of ammonium metatungstate (AMT) and WO₃ as W precursors often leads to oxygen contamination, which degrades the mechanical and electrical properties of the copper matrix. To address this issue, the alloy Cu-Y-W-O composite powders were subjected to hydrogen reduction at 600°C and 800°C, followed by densification through spark plasma sintering (SPS). The results demonstrate that hydrogen reduction at 800°C more effectively eliminates oxygen impurities and inhibits the formation of Y-W-O compounds, leading to a uniform dispersion of Y₂O₃ and W particles. The AMT sample achieved a tensile strength of 337 MPa and an elongation of 28%, while the WO₃ sample reached 365 MPa and 19%. Both electrical conductivity and densification were significantly enhanced after reduction. This study underscores the importance of high-temperature hydrogen reduction as a key step in refining the microstructure and improving the overall performance of Cu-Y₂O₃/W composites.