Microstructure and mechanical properties of Cu-base amorphous alloy matrix composites consolidated by spark plasma sintering

Cu-base amorphous alloy matrix composites were consolidated in a spark plasma sintering (SPS) facility. Amorphous powders were mixed with 10-40 vol.% of pure Cu powders, and were consolidated at 460 °C for 30 s under 300 and 700 MPa. The consolidated composites containing Cu particles homogeneously distributed in the amorphous matrix showed a considerable amount of plastic strain because of the presence of ductile Cu particles, although their compressive strength was lower than that of the monolithic amorphous alloys. The compressive strength and plastic strain of the composites consolidated under 700 MPa showed 10-20% and 100% increases, respectively, over those of the composites consolidated under 300 MPa. The increase in consolidation pressure could play a role in sufficiently bonding prior amorphous powders, in preventing micropores, and in suppressing the formation of nanocrystalline or crystalline phases. These findings suggest that composites consolidated by the SPS present new possibilities of application as structural materials offering excellent mechanical properties and satisfying large-size requirements.