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In the present work, the tensile properties at 77 K of the 0.3 wt% nano‐sized TiCp/Al–Cu composite is investigated to explore its potential application at cryogenic temperature. The TiCp/Al–Cu composite exhibits superior ultimate tensile strength (620 MPa), yield strength (531 MPa), and fracture strain (7.2%) at 77 K. The addition of TiCp leads to the refinement of θ′ precipitates and enhanced dislocation strengthening effect, contributing to the improved tensile strength. [ABSTRACT FROM AUTHOR]

The Al-Cu-Mg-Si matrix composites reinforced with in situ hybrid-sized TiC x -TiB 2 particles with sizes ranging from 20 nm to 1.3 µm were successfully synthesized using the Al-Ti-B 4 C reaction system via a method that combined the combustion synthesis and the hot press assisted with hot extrusion. The sizes of the fabricated TiC x and TiB 2 particles increased with increasing TiC x -TiB 2 content. The hybrid-sized TiC x -TiB 2 particles improved the elevated-temperature yield strength ( σ .2 ), the tensile strength ( σ UTS ), and the fracture ductility ( ε f ) of the composites at both 493 K and 573 K. The 40 wt% (TiC x -TiB 2 )/Al-Cu-Mg-Si composite exhibited superior σ .2 (141 MPa), σ UTS (164 MPa), and ε f (31.2%) at 573 K, with enhancements of 60.2%, 72.6%, and 22.4% compared to the Al-Cu-Mg-Si matrix alloy (88 MPa, 95 MPa, and 25.5%). The improvement of the elevated-temperature mechanical properties for the in situ (TiC x -TiB 2 )/Al-Cu-Mg-Si composites was attributed primarily to the strengthening effects induced by the hybrid-sized TiC x -TiB 2 particles and the θ′ precipitation strengthening. [ABSTRACT FROM AUTHOR]

The bimodal-sized (micron+nano) TiC p /Al-Cu composites were successfully fabricated by adding the in situ micron-sized and nano-sized TiC p -Al master alloys into the molten Al-Cu alloy. The composites reinforced with bimodal-sized TiC p exhibited finer α-Al grains and smaller θ′ precipitates, and possessed enhanced room- and high-temperature strength and relatively high ductility compared with the Al-Cu matrix alloy and their counterparts reinforced with monomodal-sized TiC p . The improved tensile properties may be attributed to the more significant precipitation strengthening due to the smaller θ′ precipitates, grain refinement and strengthening effects of the nano-sized and micron-sized TiC p . [ABSTRACT FROM AUTHOR]

Adding various amounts of nano-sized TiC p (0.1–0.7 wt%) made a simultaneous improvement in high-temperature strength and ductility of the Al-Cu matrix alloy. The influences of temperature and strain rate on the high-temperature tensile properties and θ′ precipitate sizes in the Al-Cu matrix alloy and the nano-sized TiC p /Al-Cu composites were investigated. Theoretical calculations suggest that the yield strength increment of the composites at 453 K was primarily attributed to the strengthening effect of both the refined θ′ precipitates and TiC p , while at 493 K only the strengthening effect of TiC p was predominant due to the significant coarsening of θ′ precipitates at this temperature. [ABSTRACT FROM AUTHOR]

We report a new rolling route combining one pass of hard-plate rolling and two passes of conventional rolling. This route is efficient in achieving near-spherical Mg 17 Al 12 phase (~0.5 µm) and uniform fine-grained structure (~3 µm) featuring a weakened texture in AZ91-0.4Sn plates after a total thickness reduction of ~86.4% via 3 rolling passes. Moreover, the processed alloy exhibited superplasticity-like fracture strain of ~96% at 200 °C, owing to fine α-Mg grains distributed with a high volume fraction of Mg 17 Al 12 . This new route significantly reduces rolling passes and hence has a great potential for industrial production. [ABSTRACT FROM AUTHOR]

Inspired by nacre, we designed biomimetic metal–ceramic composites in which hard and ductile phases were alternately arranged. We first prepared lamellar-structured TiC scaffolds with 25, 30 and 35 vol% solid loadings using a unidirectional freeze casting technique and then measured wetting and infiltration dynamics for a commercial Al cast alloy, ZL107, with the main composition of Al–7Si–5Cu on the porous TiC scaffold using a modified sessile drop method at 850 °C. The wetting was affected by liquid spreading at horizontal surface and infiltration in depth, while the latter played a dominant role in the decrease in contact angle. On the basis of the wetting results, the lamellar ZL107/TiC composites were successfully fabricated by pressure infiltration of the molten ZL107 alloy into porous TiC scaffolds and their mechanical properties were evaluated. The compressive strength and elastic modulus increased while bending strength decreased with increasing TiC content, giving maximum values of 1166 ± 20 MPa, 205 ± 2 GPa and 363 ± 5 MPa, respectively. Formation of (Al m ,Si 1 − m ) 3 Ti, Al 3 Ti and Al 4 C 3 phases in the composites was presumed to deteriorate the toughness of the composites, leading to brittle fracture under loading. [ABSTRACT FROM AUTHOR]