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Hot deformation tests of 14Cr oxide dispersion strengthened (ODS) steel fabricated by mechanical alloying and hot isostatic pressing (HIP) were performed on a Gleeble-1500D simulator at temperatures ranging from 1050 to 1200 °C with the strain rate range of 0.001−1 s−1. The relationship between the rheological stress and the deformation condition was studied, and a processing map at the true strain of 0.5 was proposed. Microstructure evolution during the deformation process and the effects of deformation conditions on microstructures were also investigated, as well as the stability of nanoparticles. Results show that the 14Cr ODS steel possesses positive strain rate sensitivity. The flow stress increases with the decrease of deformation temperature and the increase of strain rate. The recrystallization process is promoted by the increase of deformation temperature and the reduction of strain rate. Nanoparticles possess excellent stability during the deformation process and are coherent with the matrix. [ABSTRACT FROM AUTHOR]

A correction to the article "Impact of Interface Thermodynamics on Al-Induced Crystallization of Amorphous Six-Ge1-xalloysnanoparticles" that was published in the journal in 2014 is presented.

It is demonstrated that a transition from paramagnetic behavior to clear room-temperature ferromagnetism (RTFM) exists in pure bulk ZnO. A significant enhancement of RTFM has been observed in argon-annealed ZnO samples. Quantitative chemical analysis unambiguously indicates that oxygen-related vacancies at surface play a crucial role in this observed RTFM. We suppose that the surface magnetic states, paramagnetic in the pure nanoparticles, are converted to ferromagnetic phase after mechanical compaction. Additionally, it is found that weakly adsorbed carbon species could block the exchange coupling between isolated magnetic moments in the surface layers. [ABSTRACT FROM AUTHOR]

Developing cost effective, active and durable alternatives to platinum electrocatalysts is the major challenge for sustainable hydrogen production. Rational design and controlled synthesis of hybrid structures with strong metal-support interaction may offer a feasible strategy to achieve efficient and stable hydrogen evolution reaction (HER). Herein, a low cost and high-performance ultrafine Ru nanoparticles anchored tungsten carbide (Ru/WC) HER electrocatalyst is successfully prepared by high-temperature shock (HTS) technology, which can be accomplished in less than 0.5 s. In a strong alkaline medium, the as-prepared Ru/WC exhibits a low overpotential of 4 mV and 72 mV at the current densities of 10 mA cm−2 and 100 mA cm−2, respectively. Low Tafel slope of 44 mV dec−1, high turnover frequency (TOF) of 2.55 s−1 at an overpotential of 100 mV, long-term electrochemical stability up to 150 h, and ampere-level current density can be achieved. Furthermore, Ru/WC also shows exceptional activity and stability under acidic conditions. Notably, Ru/WC can accommodate HER current density as high as 2000 mA cm−2 at a small overpotential of 365 mV, which holds great promises for industrial large-scale production. This work provides a simple, rapid, and solvent-free strategy for synthesizing high efficiency HER electrocatalyst with ampere-level current density. [Display omitted] • Ultrafine Ru nanoparticles anchored tungsten carbide (Ru/WC) was prepared by high-temperature shock technology. • Ru/WC displays quite small HER overpotentials and large TOF value in alkaline and acid solution. • Ru/WC can reach ampere-level current density of HER at low overpotentials in alkaline and acid solution. • The metal-support interaction between ultrafine Ru and WC contributes to the excellent HER performance. [ABSTRACT FROM AUTHOR]

WC dispersion-reinforced Cu composites with high thermal stability were fabricated using intermittent electrodeposition and the spark plasma sintering (SPS). WC nanoparticles were dispersed uniformly due to the formation of the Cu cladding WC structures. The pin and impurity drag mechanisms contributed by the dispersed WC impeded the migration of grain boundaries. Based on the kinetic analysis, the improved grain-growth activation energy was observed for 3.0 wt% WC-reinforced Cu (up to 376.4 ± 3.7 kJ/mol), which is over three times higher than that for self-diffusion in pure Cu. The yield strength of this composite increased to 282.9 MPa at 300 °C, which is nine times higher than the value in Cu. This work provides an advanced pathway for designing thermal stable Cu composites for application as heat sinks. [Display omitted] [ABSTRACT FROM AUTHOR]

Unlike conventional amorphous materials without grain boundaries and dislocations, nanoglasses consist of amorphous nanoparticles and glass-glass interfaces, which results in unique properties. In this work, we have developed a ZrO 2 –Cu composite nanoglass by multi-target magnetron co-sputtering, and its microstructure, optical and electrical properties have been studied by using aberration-corrected transmission electron microscope, spectroscopic ellipsometry, UV–Visible spectrophotometer and Hall measurements. It is found that Cu is enriched into the amorphous interfacial region. The ZrO 2 –Cu composite nanoglass shows high visible light transmittance (over 70%), high refractive index (1.98–2.08) and large optical band gap (5.0–5.7 eV). As the Cu content increases, the electrical properties are also improved. The enrichment of Cu at the interface further provides a new route for the preparation of 2D nano-conducting networks. • A new system of nanoglasses — metal-oxide (Cu–ZrO 2) composite nanoglass, is reported. • Cu is enriched into the amorphous interfacial region. • High transmittance, high refractive index and large optical band gap are achieved. • The electrical properties are improved as compared to pure ZrO 2. [ABSTRACT FROM AUTHOR]