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In addition to wave‐based fields, metamaterials can manipulate diffusion fields at will, for example, the scattering cancellation of particle flow in natural materials. In this paper, a monolayer cloak is proposed to eliminate electron scattering and improve the total conductivity in commonly used aluminum‐oxide‐dispersion‐strengthened copper alloys (Cu‐Al2O3) after a multiscale model is established to theoretically explain the dependence of conductivity on scattering behavior. Intense electron scattering caused by dispersed alumina nanoinclusions dominates the drastic drop in the conductivity in the Cu‐Al2O3 system. The Drude model is expanded to a generalized form to explain the multiscale scattering regime in Cu‐Al2O3 after unifying the macro‐ and nanoscale considerations into the mesoscopic multibody scattering process of a Monte Carlo simulation. The results indicate that the conductivity is closely related to the overall electron density and relaxation time of electrons. Then, a cloak is designed based on scattering cancellation to improve the conductivity by reducing electron collisions, whose structure is simplified into a monolayer cloak by adopting an imaginary insulating layer. Both simulation and experiment confirm a substantial improvement of the total conductivity. The invisible cloaks manipulating particle flow expands the research scope of metamaterials to innovatively improve the properties of traditional materials.

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In this paper, powder metallurgy (PM) H13 steels were investigated based on the characterisation of water atomised H13 powders. Vacuum sintering was carried out from 1150 to 1265°C for sintering densification. The relative density of the as-sintered sample reached to 95% and mechanical properties were released above 1200°C. To eliminate the residual pores, subsequent forging was performed. The relative density increased to above 99%. As the concentration of Si elements on the powder surface was higher than the nominal composition, there was Si segregation in the form of silicon oxides (1-3 μm).Although oxide particles such as SiO 2 were inevitable, the mechanical performance of PM H13 steels was still comparable to that of ingot metallurgy products. The tempered PM H13 steels exhibited high tensile strength of 1460 MPa in YS, 1737 MPa in UTS and 8.7% in elongation. Besides, the impact toughness was as high as 14.7 J cm −2 .