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Co nanowires have been electroplated into porous Al2O3 templates. The crystalline structure and magnetic properties of Co nanowires of diameters 65 and 200 nm have been studied. Long single crystal Co segments with a hexagonal closed-packed (hcp) structure have been found in the 65 nm-thick nanowires. A mixture of face-centered cubic and hcp single crystal Co segments was observed in the 200 nm-thick nanowires. This finding suggests that the small template pore size favors the growth of hcp Co phase. Magnetic force microscopy measurements showed longitudinal spontaneous magnetic moments in the 65 nm-thick nanowires and transverse moments in the 200 nm-thick nanowires. [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]