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To improve the surface hardness and wear resistance of Al-Pb alloys, pure aluminum (Al) surfaces coated with lead (Pb) layers were irradiated by using high current pulsed electron beam (HCPEB) to prepare Al-Pb alloyed layers with excellent properties. The surface roughness of the alloying layer was observed by 3D laser scanning microscope (LSM). Meanwhile, the micro morphology, structure and element distribution of Al-Pb coating before and after irradiation alloying were analyzed by field emission scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS). In addition, the phase composition of the alloy layer was observed by X-ray diffraction (XRD). Moreover, the surface microstructure after alloying was characterized by transmission electron microscopy (TEM). Finally, the microhardness, average friction coefficient and wear rate of the sample surface before and after irradiation were tested, and the hardness and wear enhancement mechanism were analyzed. The strengthening mechanism of the surface performance was also summarized. The internal relationship between surface microstructure and surface properties of irradiated coatings was established. The results show that after HCPEB irradiation treatment, the Al substrate and Pb coating show good metallurgical bonding, and after 30 times of irradiation, the Pb-Al alloying layer with a thickness of about 10.2 μm is prepared. Compared with pure aluminum and the original coating, the diffraction peak of (111)Al crystal plane is widened after 30 times of irradiation, and the position of the diffraction peak is also slightly shifted to the low angle direction, which means that the Al grains on the surface of the matrix are significantly refined after the surface alloying treatment of HCPEB, and the crystal cells expand, and the lattice constant increases. HCPEB induces the formation of sub crystals, dislocations, dislocation cells, a small amount of Al(Pb) solid solution and a large number of nanoscale Pb rich particles on the sample surface. The test results show that the hardness and wear resistance of Al-Pb coating surface are significantly improved after electron beam irradiation.

Sn-doped indium oxide (ITO) semiconductor nano-films are fabricated by plasma-enhanced atomic layer deposition using trimethylindium (TMIn), tetrakis(dimethylamino)tin (TDMASn), and O2 plasma as the sources of In, Sn and O, respectively. A shared temperature window of 150 °C– 200 °C is observed for the deposition of ITO nano-films. The introduction of Sn into indium oxide is found to increase the concentration of oxygen into the ITO films and inhibit crystallization. Furthermore, two oxidation states are observed for In and Sn, respectively. With the increment of interfaces of In–O/Sn–O in the ITO films, the relative percentage of In3+ ions increases and that of Sn4+ decreases, which is generated by interfacial competing reactions. By optimizing the channel component, the In0.77Sn0.23O1.11 thin-film transistors (TFTs) demonstrate high performance, including μ FE of 52.7 cm2 V−1 s−1, and a high I ON/ I OFF of ∼5 × 109. Moreover, the devices show excellent positive bias temperature stress stability at 3 MV cm−1 and 85 °C, i.e. a minimal V th shift of 0.017 V after 4 ks stress. This work highlights the successful application of ITO semiconductor nano-films by ALD for TFTs. [ABSTRACT FROM AUTHOR]

BackgroundCu-W composites are widely used in electric power, electronics, and plastic forming owing to the excellent electrical and thermal conductivities of copper combined with the outstanding strength and thermal properties of tungsten.PurposeThis study aims to investigate the extension of the solid solubility of the Cu-W immiscible system under high current pulsed electron beam (HCPEB) irradiation.MethodsFirst of all, the Cu-15W powder mixture was sintered by vacuum at 850 ℃ after ball milling for 5 h to prepare the Cu-W composites. After polishing, the Cu-W composites was exposed by a HOPE-1 type HCPEB device with 1, 5, 10 and 15 pulses, respectively. Then, Rigaku D/Max-2500/pc X-ray diffractometer (XRD) was used to analyze the phase constitutes of the milling powder, sintered samples and irradiated samples. The surface morphology was observed by JEOL JSM-7001F field emission scanning electron microscope (SEM). The energy dispersive spectrometer (EDS) in SEM was used for the examination of micro-region composition. Finally, the microstructures in the modified layer were characterized by JEOL-2100F transmission electron microscopy (TEM). The surface hardness of the sintered and irradiated samples with different pulses was measured using the HVS-1000 Vickers hardness tester.ResultsThe results reveal that Cu(W) solid solutions were formed during the process of ball milling, and the mass fraction of the solute element W in the Cu(W) solid solution reaches 0.88% after 5 h of ball milling. It was discovered that the solid solution undergoes exsolution reaction during heating using differential scanning calorimeter (DSC). The sintered sample surface was irradiated by a pulsed electron beam. The results demonstrate the formation of solid solution phase after HCPEB irradiation, whose solubility increases with the increase of the number of pulses. After 10 pulse irradiations, the mass percentage of solute element (W) in Cu(W) solid solutions reaches 1.63%. The surface hardness of irradiated samples increases significantly after HCPEB irradiation, and reaches 237.1 HV after 10-pulsed irradiation. Surface hardening is primarily caused by of solid solution strengthening and dispersion strengthening.ConclusionsThe present paper provides a meaningful instruction for preparing the immiscible alloy with high solid solubility and the excellent performance.

Carbon nanomaterials have attracted much attention in the field of science and technology for their excellent properties; however, developing a simple, environmentally friendly, and versatile synthesis strategy for the preparation of carbon nanomaterials with novel structures remains a great challenge. Herein, a surfactant @ salt (dodecyltrimethylammonium bromide DTAB @ NaCl) self‐assembly strategy for the synthesis of carbon nanomaterials with novel structures, i.e., carbon nanoframes is reported. The synthesis differs from the traditional template method in that it is characterized by the introduction of surfactants for separation and protection, and the salt can be recycled. In addition, the carbon frame size in this system can be adjusted on demand by simply adjusting the concentration of surfactant, thus realizing that the carbon nanoframe size is adjustable in the range of 232.58–322.51 nm. Impressively, the carbon nanoframe has purple, blue, and green PL emission behavior. It is anticipated that this research will provide new insights into the development of novel carbon nanomaterials. [ABSTRACT FROM AUTHOR]

A detailed investigation concerning the formation mechanism of craters of pure metal and alloy surface after high-current pulsed electron beam (HCPEB) processing has been carried out. After HCPEB irradiation, typical craters were homogeneously distributed on the entire surface of 3Cr13 stainless steel, resulting from local sublayer melting and eruption through the solid outer surface. Comparatively, almost no craters were created of pure zirconium, which was associated with the shallow melting site and incomplete treated surface. Furthermore, a large number of ultrafine grains were formed on the irradiated surface, indicating that surface melting was the dominant interaction mechanism between HCPEB irradiation and pure zirconium. It is apparent that “crater free” phenomenon plays a dominant role in surface modification of zirconium and zirconium alloys.