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The Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2C-M x C composite ceramic was prepared by hot pressed sintering with the Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2C high entropy carbide as the main phase. Secondary phase M x C (M=Ti, Zr, Hf, Nb, Ta) was found to be distributed relatively uniform in composite ceramic. The oxidation behaviour of the ceramic was examined after exposure to 923 K and 1173 K. The morphology of the surface and cross-sections of all oxidation samples were observed. The characteristics of the oxidation behavior about high entropy carbide and secondary phase M x C were compared and analyzed. The secondary phases (such as Ti-rich carbide or Hf-rich carbide) in the material were seriously oxidized at 923 K and 1173 K, which reflects the superior oxidation performance of high entropy carbide. The nano high entropy oxides with Ti, Zr, Hf, Nb, Ta, O elements were discovered by oxidation of the composite ceramic. The above research is helpful to deepen the understanding of the oxidation mechanism of high entropy carbide and the composite ceramic.

Vanadium alloys are regarded as promising candidate structural materials for the advanced blanket concept in fusion reactors due to their low activation, good high-temperature strength and, in particular, their compatibility with liquid lithium. In the present work, six kinds of V–5Cr–5Ti alloys under heavy cold work with deformation amounts of 40%, 60% and 80%, and/or subsequent annealing were investigated. Irradiation damage of 0.1, 0.3 and 0.5 dpa was introduced in both specimens using 352.8 MeV Fe ions at 100 °C. Electron backscattered diffraction and transmission electron microscopy (TEM) were used to investigate pre-irradiation microstructures such as grains, dislocations, precipitates and bubbles. X-ray diffraction was used to evaluate the pre-existing dislocation density and TEM was used to image the irradiation defects. The change in hardness was evaluated using micro-hardness tests. Before irradiation, the hardness increased with the increasing deformation amount but decreased after subsequent annealing. Dislocation cells turning into sub-grains with low-angle boundaries were observed, while the deformation amount reached 80% in cold-worked specimens. After irradiation, hardening was observed in all specimens and at all irradiation doses, and a power-law relation was observed in dose-dependent hardening. The effect of the initial microstructure on irradiation hardening was discussed in terms of the sink strength while ignoring grains and precipitates due to their large size. Pre-existing bubbles could effectively reduce irradiation hardening compared with previous results. Meanwhile, with the increasing sink strength of dislocations, hardening decreased in a different manner in cold-worked and annealed specimens. The irradiation defects in some specimens were investigated to clarify the inherent mechanism in the relationship between the initial microstructures and irradiation hardening.

In the application of additive manufacturing, it is inevitable to use some formed parts with a smaller height. The analysis of various mechanical properties of these formed parts is the focus of research. In this paper, the fatigue performance of a titanium alloy specimen with a 10 mm height and electron beam selective melting is studied. By analyzing the structure and phase of the overall fatigue specimen, and then cutting the overall specimen parallel and perpendicular to the additive manufacturing direction, the tensile and fatigue tests in different directions are performed to detect the fatigue cracks at the fracture propagation the way to research. It is found that there are two ways of secondary crack propagation between fatigue bands, and three cracks are generated during the fatigue secondary crack propagation.

Short carbon fiber reinforced aluminium based matrix composites were fabricated by a low-pressure infiltration process. This study is amid for development of short carbon fiber reinforced aluminium matrix composites. Short carbon fibers of 10 vol.% was used to preparing preforms for the low-pressure infiltration process. Afterwards, pure Al and Aluminium alloy under temperature of 1073K were infiltrated into the preforms under an applied pressure of 0.4MPa. Microstructure and Vickers hardness as well as microstructure–property relationships of these materials were studied. Microstructure observations indicated that: the SiO2 binder was coating on the surface of short carbon fiber and distributed at the corner of carbon fibers in preforms. Short carbon fibers were homogeneously distributed in the matrix. Furthermore, properties of short carbon fiber reinforced pure Al and A336 alloy composites showed that: the relative density was 95.8% and 97.2%, respectively. Hardness of short carbon fiber reinforced pure Al composite increased by 76% comparing to the base pure Al, and short carbon fiber reinforced A336 alloy composite increased by 10% comparing to the A336 alloy.

The D(d,p)T reaction in Be metal environments has been measured to investigate the electron screening effect in metals in an energy region of from 5.5 keV to 10 keV in a center of mass system (CMS) at a temperature of 121 K. The depth distribution of deuteron density in Be metals has an impact on the observed reaction yields. A model of deuteron density distribution in metal has been proposed to obtain the original yields. A screening energy of (116±46) eV has been obtained with the assumed deuteron density distribution model.

The in situ observation of Au dot formation and the self-assembly dynamics of Au nanoparticles (NPs) was successfully demonstrated via dewetting of Au thin films on SiO2 glass substrates under nano-second pulsed laser irradiation using a multi-quantum beam high-voltage electron microscope. Moreover, using electron energy-loss spectroscopy (EELS) performed in a scanning transmission electron microscope (STEM), the plasmonic properties of the formed Au/SiO2 nanostructure were analyzed to demonstrate its validity in advanced optical devices. The uniformly distributed Au NPs evolved into a dot alignment through movement and coalescence processes was demonstrated in this in situ observation. We carried out the plasmon-loss images of the plan view and the cross-section of the Au/SiO2 nanostructures were obtained at the plasmon-loss peak energy for investigate the three-dimensional distribution of surface plasmon. Furthermore, discrete-dipole approximation (DDA) calculations were used to simulate the plasmonic properties, such as the surface plasmon resonance and the surface plasmon field distribution, of isolated single Au/SiO2 nanostructures. This STEM-EELS-acquired surface plasmon map of the cross-sectional sample is in excellent agreement with the DDA calculations. This results demonstrated the influence of the contact condition between Au NP and SiO2 glass on the plasmonic properties, and may improve the technology for developing advanced optical devices.

The deuterium depth distribution for a , while beam implanted into ytterbium (Yb) at a temperature between 300 and 340 K was studied using the D(d,p)T reaction. By analyzing the proton yields, the deuterium depth distribution from the front surface to 500 nm depth was found. The results indicate that an equilibrium deuterium distribution region from the front surface to a depth approximately equal to the mean range of implanted deuterons was formed in Yb during the implantation. The deduced deuterium concentration in the equilibrium deuterium distribution region was D/Yb = 22%.

A new instrument of broadband solar radio spectrometer working at waveband 4.5-7.5 GHz was developed at Purple Mountain Observatory for Solar Maximum 23. Some new results of spectral observation have been obtained since August 1999. Two typical type III mu bursts with rich fine structures are presented and some interesting features discussed.