Abstract: Some latest research progresses on the potential negative impacts of engineered nanomaterials on human health and the environment are reviewed. Open problems about such aspects are addressed.
Abstract: This paper covers the analysis of amorphous alloys CoP-CoNiP system by means of high-resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy and electron tomography. The last years have seen a sufficient progress in the analysis of nanomaterials structure with the help of high resolution tomography. This progress was motivated by the development of microscopes equipped with aberration correctors and specialized sample holders which allow reaching the tilts angles up to ±80°. The opportunities delivered by the method of electron tomography sufficiently grow when producing high resolution images and using chemical analysis, such as X-Ray energy-dispersive microanalysis and electron energy loss spectroscopy (EELS).
Abstract: This paper covers the investigation of the microstructure and magnetic properties of amorphous magnetic alloy Fe78Ni1Si9B12 films, which was subjected to thermal processing. Study of the surface with the help of phase analysis and Kikuchi-diffraction revealed the change of state of the alloy surface without the influence on its volume.
Abstract: Hard machinability of titanium alloys severely limits its development in the field of aviation. It has been proved that micro-texture has a good effect on friction-reducing in turning under the conditions of Minimum Quantity Lubrication (MQL). In this paper, cutting tool with micro-texture on its rake face is fabricated and then experiments are carried out under the conditions of dry continuous turning titanium alloys. A dynamometer is set under the workpiece to measure three components of the cutting forces and the data is processed by Business software MATLAB. Average coefficient μ is calculated according to the mechanical model. Experimental results show that under the dry conditions, micro-texture plays a role in the specific cutting parameters while losing its role in most cases. Also the reasons which lead to the failure of improving the friction properties are analyzed.
Abstract: To achieve reasonable rolling technology of the novel Nb-V composite microalloyed steel, the continuous cooling transformation (CCT) curve was established by thermal simulation experiment. Microstructure and microhardness at different cooling rates were characterized using an optical microscope (OM) and microhardness tester. The results indicate that the critical quenching speed of Nb-V microalloyed steel is about 23 °C/s. The start and finishing temperatures of phase transformation decreased with the rise of cooling rate. Widmannstatten (W) structure appears at lower cooling rate interval. Microstructure transfers into martensite (M) and bainite (B) with obviously refined grains in higher cooling rate interval. Microhardness improves with the increase of cooling rates. Microhardness value is greatly improved to 298.6 HV at the cooling rate of 11 °C/s, which could be related to the formation of lower bainite during phase transformation process. When the cooling rate is above 29 °C/s, microhardness values remain unchanged basically. This illustrates that the microstructure of Nb-V microalloyed steel consists of martensite and lower bainite.
Abstract: Double-sided double arc welding (DSDAW), a high efficiency method for welding thick plate of low alloy high strength steel which does not require back chipping is used in this paper, research on multi-pass route planning for thick plate of low alloy high strength plate by double-sided double arc welding. Firstly, establish a double-sided double arc welding system that can realize thick plate of low alloy high strength steel double-sided double arc welding by double robots. Then, Propose the multi-pass route planning for thick plate of low alloy high strength steel by double-sided double arc welding by means of misplaced welding. According to the welding parameters and the geometry size of groove, plan the layers, the number of beads and the concrete position of the welding torch for each bead. Finally, the welding experiment has been done to verify the effectiveness of multi-pass route planning. The results of welding experiment are approximately agreement with the multi-pass route planning results. The backing weld can get better appearance in the front and guarantee fusion penetration in the back simultaneously. On the basis of the multi-pass welding route planning, good fusion and leveling interface can be obtained after filler passes.
Abstract: In this paper, SnS2, SnS2:Cu and SnS nanocrystals were prepared by hydrothermal method and the thin film solar cell with the novel structure of FTO/SnS2:Cu/ SnS/Sn was fabricated by dipping-coating technique. The thin film solar cell gave the short circuit photocurrent density of 37.5 μA·cm−2, open circuit voltage of 130 mV, and fill factor of 0.35, corresponding to the photoelectric conversion efficiency of 0.17 %.
Abstract: In this paper，CdTe thin films were successfully grown at higher source temperatures of 650 °C and 700 °C using close-spaced sublimation(CSS) and characterized by energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis-NIR absorption spectra, respectively. The results indicated that the grain size of CdTe thin film increased from 1 μm to 5 μm with the increase of the source temperature from 650 °C to 700 °C. The direct band gaps of CdTe thin films prepared at different source temperatures of 650 °C and 700 °C were 1.44 and 1.43 eV, respectively.
Abstract: In the present study, a new nanocomposite coatings, Ni-CeO2, has been prepared by electrodepositing. The effect of current density on the CeO2 particles included into the deposits, morphology, preferred orientation, wear resistance and high temperature oxidation resistance has been studied. The investigated results demonstrate that the weight percent of particles in the nanocomposite coatings varied with a rise in current density, and the maximum weight percent of CeO2 particles in the coatings is 4.97 wt% obtained at the current density of 1 Adm-2. The paper firstly presents that the high temperature oxidation resistance of nanocomposite coatings is closely related to the current density, at which the nanocomposite coatings were electrodeposited, and the best high temperature oxidation resistance was acquired at the current density of 1 Adm-2