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• The incoherent B 4 C/Al 2 O 3 phase interface was replaced by the well-bonded semi-coherent B 4 C/Al interface. • Both the tensile strength and elongation of the as-rolled composite were increased compared with the as-sintered composite. • The improvement of interface Al 2 O 3 nanoparticles distribution during hot rolling improved the mechanical properties. • The dispersion of Al 2 O 3 nanoparticles in the grain improved the dislocation storage ability, hence increase the ductility. B 4 C/Al composites with a high B 4 C content of 30 wt% were successfully fabricated by hot pressing sintering followed by hot rolling. The influence of hot rolling on the microstructure, mechanical properties, anisotropy and the interfacial conditions of the B 4 C/Al composites were systematically investigated. The improvement of the interfacial Al 2 O 3 nanoparticles distribution during hot rolling increased both the strength and ductility. After sintering of B 4 C/Al composites, some Al 2 O 3 nanoparticles aggregated together at the interface between B 4 C and Al matrix, lowering the interface bonding strength between B 4 C and Al matrix. The Al 2 O 3 nanoparticles dispersed into the Al grain interior after rolling, leading to a well bonding interface between B 4 C particles and the Al matrix. In addition, the dispersion of Al 2 O 3 nanoparticles into the Al grain interior contributed to the strength through Orowan strengthening and ductility through the enhancement of dislocation storage ability. The strengthening and toughening mechanisms of the composites are discussed in detail. [ABSTRACT FROM AUTHOR]

Highlights: [•] The synthesis of Ag–NaCMC films was successfully fulfilled by a low-cost microwave method. [•] More uniform silver nanoparticles were observed in Ag–NaCMC film synthesized by microwave. [•] Improved reproducibility of SERS signal was obtained in microwave synthesized Ag–NaCMC film. [Copyright &y& Elsevier]

Abstract Three-dimensional (3D) continuous Ni-network-reinforced Ag-matrix composite materials were prepared by hot-pressing Ag–Ni composite powders with Ni powders coated on the surface of Ag granules. The formation of a 3D continuous Ni network enhances the load transferred from the Ag matrix to the second-phase Ni, inducing the co-deformation of Ag and Ni during the drawing deformation. The co-deformation begins as orientation rotation and refinement; e.g. the Ag matrix slips on {111}〈1 1 - 0〉, twins on {111}〈11 2 - 〉, and 〈100〉 drawing texture are formed in second-phase Ni along the drawing direction. Finally, the 3D continuous Ni networks were torn and drawn into belts that are parallel to the axial direction of the composite wire. Increasing the real strain could increase the length of the Ni belts in the axial direction, thus increasing the hardness and electrical conductivity of Ag–Ni electrical contact materials. Additionally, the two-dimensional characteristics of the belts with high profile drag increase the flow resistance of molten Ag. Therefore, the belt-reinforced Ag–Ni electrical contact materials show a low mass loss after 100000 times of contact (1.8 mg, only 22.8% of that of the round fibres reinforced sample). Highlights • A Ni-belt-reinforced Ag-based electrical contact material was developed. • Higher hardness than Doduco products (50–70 HV) was obtained in cross section (94.5 HV). • Elimination of segregation of Ni particles under arc erosion by the pinning mechanisms and their high profile drag. • Anti-arc erosion performance with a mass loss about 30.5% of that of a particulate-reinforced sample. [ABSTRACT FROM AUTHOR]

The effect of neodymium (Nd) additions from 0 to 0.2 wt.% on microstructure, mechanical properties at room and high temperature, as well as corrosion resistance of 2A70 alloy were studied by optical microscopy (OM), scanning electron microscope (SEM), transmission electron microscopy (TEM) in this paper. The results show that appropriate addition of Nd (0.15 wt.%) refines the size and enhances the density of the aging precipitates S′ phase, which lead to the increasing of mechanical properties at room and elevated temperatures. The newly formed Al8Cu4Nd compound, dispersed along grain boundary, which hinders the movement of grain boundaries at elevated temperature and improves the high temperature performance of 2A70 alloy. Compared with traditional 2A70 alloy, the intergranular corrosion of the peak-aged alloy with 0.15 wt.% Nd has also been effectively enhanced. [ABSTRACT FROM AUTHOR]

The strength-ductility trade-off has always been a difficult issue in the development of highperformance structural materials. In this work, a new non-equiatomic Fe 37.5 Ni 30 Co 22.5 Al 5 Ti 5 (at%) high entropy alloy (HEA) was developed, which shows both excellent strength and ductility. The yield strength of the aged HEA reached 1094 MPa, which is more than twice that of the solid-solution HEA, while the ultimate tensile strength was 1275 MPa, and the elongation to failure was ∼38%. The high yield strength resulted from precipitation strengthening provided by a high number density of L1 2 -Ni 3 (Al, Ti) nanoprecipitates. Both a small grain size and the nanoprecipitates can induce high local stresses, enhancing the phase transformation from face-centered cubic (FCC) to martensite that occurs in this HEA, and which can lead to the good ductility. As much as possible to keep strength-ductility through the coupling between precipitation strengthening and TRIP effect is a suitable strategy to overcome the strength and ductility trade-off. • The yield strength of the aged HEA is more than twice that of the solid-solution HEA with the elongation loss of only ∼19 %. • Under the coupling between precipitation strengthening and TRIP effect, the AG HEA shows excellent mechanical properties. • The nanoprecipitates change the SFE of the matrix and promote the occurrence of phase transformation to some extent. [ABSTRACT FROM AUTHOR]