Mechanical behaviour of ultrafine grained Cu and Cu-(2.5 and 5) vol.%Al₂O₃ composites produced by powder compact forging

Nanostructured Cu-(2.5 and 5) vol.%Al₂O₃ composite powders were produced from a mixture of Cu powder and Al₂O₃ nanopowder using high energy mechanical milling, and then compacted by hot pressing. The Cu and Cu- Al₂O₃ composite powder compacts were then forged into disks at temperatures in the range of 500-800°C to consolidate the Cu and Cu- Al₂O₃ composite powders. Tensile testing of the specimens cut from the forged disks showed that the Cu forged disk had a good ductility (plastic strain to fracture: ~15%) and high yield strength of 320 MPa, and the Cu-(2.5 and 5)vol.%Al₂O₃ composite forged disks had a high fracture strength in range of 530-600 MPa, but low ductility