The sintering characteristics of the Cu-γ₂(Cu₉Al₄)-Ni system mixed powder compacts, composed of Cu and Ni metallic powders γ₂ alloy powders and (Cu-Ni) and (γ₂-Ni) composite powders, which are respectively those of Cu and γ₂ composite chemically plated with Ni, have been dilatometrically investigated. The mechanical properties of these sintered compacts at different sintering conditions were measured.
The results obtained were summarized as follows.
(1) The (Cu-Ni)-γ₂ mixed powder compacts were contacted, but the other mixed powder compacts swelled during the conventional sintering.
(2) The above (Cu-Ni)-γ₂ compact sintered at 1000°C for 60 minutes showed the tensile strength of 12.5 kg/mm², the elongation of 4% and the hardness (R_H) of 70.
(3) By repressing and resintering or by hot repressing, these mechanical properties were remarkably improved, especially after the hot respressing at 900°C by 400 kg/cm² for 30 minutes, the tensile strength, elongation and hardness (R_H) obtained were 30.5 kg/mm², 13% and 96.5 respectively.