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The balance between strength and toughness is of great importance. In this paper, the microstructure and properties of laminated composites in X-Y direction were characterized and analyzed. The effect of the content of α-Al2O3w and MWCNTs on the laminated structure and properties was analyzed, and strengthening mechanisms and toughening mechanisms of the material were discussed. The laminated structure of traditional Cu matrix composites was designed by a combination of flake powder metallurgy and SPS sintering. Compared with spherical Cu, flake Cu can increase the interface contact between matrix and reinforcement phase, which is conducive to the formation of self-assembly of laminated structure in SPS sintering process. The strength and compressive elongation of 1.0 wt.% MWCNTs-1.0 wt.% α-Al2O3w/Cu hybrid laminated composites were the best, reaching 453.43 MPa, 50%, respectively. This is mainly due to the composites containing MWCNTs less than 1.0 wt.% had uniform microstructure and good interfacial bonding, and the loads were effectively transferred from Cu matrix to MWCNTs and α-Al2O3w. At the same time, the large grain size in the plane is favorable for dislocation movement, while the interlayer interface and nanocrystals hinder the combination of dislocation movement perpendicular to the plane to achieve a balance of strength and toughness. [ABSTRACT FROM AUTHOR]

Inspired by the hierarchical structure of the pearl shell and its related multi-scale toughening mechanism, based on the combination of powder metallurgy technology and spark plasma sintering, a layered graphene and carbon nanotubes hybrid reinforced Cu matrix composite material was successfully prepared. Compared with other conventional Cu matrix composite materials, the compressive elongation of the bionic materials is significantly improved, and all of them are above 20%, which is attributed to the effective crack deflection and the pull-out of the reinforcing phase. In terms of overall strength and toughness, (0.8 wt% MWCNTs+0.2 wt% GNPs)/Cu has the best performance. Its tensile strength, compressive strength and compressive elongation are 103.63 MPa, 202.32 MPa and 33.49% respectively. The large grain size in the laminates is conducive to the movement of dislocations, while the interlayer interface and nanocrystalline grains hinder the movement of dislocations in the direction perpendicular to the laminates. The layered nano-carbon reinforced Cu matrix composite material was successfully prepared by using flake powder metallurgy. It is determined that the imitation pearl shell structure is toughened by the extraction of nano-carbon and the deflection of cracks. [Display omitted] • The composite effectively balances relationship between strength and toughness. • The interface bonding of the composites is mainly mechanical bonding. • Flake powder metallurgy is an effective strategy for layered composites. [ABSTRACT FROM AUTHOR]

In this work, α-Al 2 O 3 whisker reinforced Cu-graphite matrix composites were prepared by spark plasma sintering. Results show that the surface modification of α-Al 2 O 3 whiskers with sodium dodecyl sulfate solution can improve its dispersibility, and the composites obtained are basically completely dense. The relative density of all composite materials is above 95%. The interface bonding mode in the composite is mainly mechanical bonding, and the formation of a diffusion layer is also observed from interfaces. With the increase of α-Al 2 O 3 whisker content, mechanical properties of the composites increase first and then decrease. The composite with 1.0 wt% α-Al 2 O 3 whisker has the best performance. The corresponding relative density, hardness and compressive strength are 96.35%, 56.20 HV, 139.12 MPa, respectively. By analyzing microstructure and fracture morphology of the composites, it is determined that the strengthening mechanisms are mainly fine grain strengthening, particle strengthening and load transfer. Simultaneously, the fracture type is brittle fracture. Unlabelled Image • The α-Al 2 O 3 whisker reinforced Cu-graphite composites were prepared via SPS. • The interface between the matrix and α-Al 2 O 3 whisker was analyzed. • The strengthening mechanism of Cu-graphite composites was investigated. • Fracture mechanisms of the composites were analyzed systematically. [ABSTRACT FROM AUTHOR]