Papers by Keyword: Surface Morphology

Abstract: Atomic force microscopy (АFМ) and high-precision scanning electron microscopy methods were used to study the surface of diffusion filter-membranes of alloy Pd₉₃Y₇. The formation of alterations in structure in one of membranes was established as a result from the homogenizing annealing at 900°C for 1 hours. It was found that the reversible doping of the membrane alloy with hydrogen caused the dispersion of the diffusion filter-membranes’ surface structure. Differences in changes by the surface structure are determined during the hydrogenation in directional and non-directional flow of hydrogen.

Abstract: Cu/Ti binary thin film system has many applications for micro-/nano- electro mechanical systems (MEMS/NEMS), micro-electronics and optoelectronics. In nanoscale, the quality and many physical properties of nano thin films are strongly depended on its surface morphology. In the present paper the development of surface morphology of double layered Cu/Ti thin film heterostructure with different composition and thickness has been studied by using the phase field method. The developed method is based on solving Cahn-Hilliard equations of multi-order parameters with considering the interfacial energy and elastic energy. The simulation results show that the thickness of Ti layer and Cu layer in the double-layer thin film structure can affect the surface roughness. For the heterostructures with the Cu layer thickness was fixed at 20 nm, the surface roughness was found to vary from 0.608 nm to 0.712 nm, when the Ti layer thickness increased from 10 nm to 30 nm. The calculated surface morphology and roughness was similar to the experimentally measured values. It is believed that this simulation method is useful in designing multi-layered thin film structure for practical applications.

Abstract: X-ray spectroscopic microanalysis was used to determine the concentration of titanium on the surface of the wear spot of a silicon carbide crystal during micro-scratching and the concentration of silicon on the treated surface after grinding by a wheel of silicon carbide. The wear resistance and grinding coefficient of titanium alloys under micro-scratching with single crystals and grinding with wheels made of corundum, silicon carbide, cubic boron nitride and diamond were determined. The morphology of the treated surface and the regularities of changes in the indicators of the grinding process of titanium alloys with circles of various characteristics were studied. The features of the process of grinding titanium alloys using various lubricants and coolants are shown. The influence of the characteristics of the abrasive tool and grinding modes on low-cycle fatigue on the operation of flat and round grinding of samples made of titanium alloys VT9 and VT22 was studied. The influence of abrasive material, grinding speed, feed and sparkout during finishing on low-cycle fatigue was analyzed. Based on the research, recommendations were given for choosing a rational characteristic of the abrasive tool and processing modes.

Abstract: Novel electronic nanomaterial, the carbon nanotube (CNT) has emerged in many sensor applications as such its state dispersion has considerable importance to ensure the sustainability of its electronic properties. In this paper, we reported a state of art conductivity mapping on nanostructure surface of single walled carbon nanotubes (SWCNT) and poly(3-hexylthiophene-2,5-diyl), (P3HT) as potential sensing film. This composite is proposed to give selective analyte anchoring across the film as well as improved carrier mobility. The easy solution processing method was chosen to produce non-covalently wrapped conducting polymer onto the surface of SWCNT. We successfully observed high resolution images of the SWCNT walls that indicated increase of the thickness due to polymer wrapping. The image obtained from conductivity atomic force microscopy (CAFM) show the film’s electrical distribution that correlated with the observed nanostructure of film. Supporting optical characteristics of the nanocomposite obtained from UV-Vis spectroscopy and Raman spectroscopy discussed the morphology of the polymer wrapping and the state of dispersion of the polymer and the nanotubes. It is hypothesized the filament structures made by P3HT/SWCNT can give better sensing performance due to modification of π-π electronic band of SWCNT.

Abstract: Magnetic abrasive finishing (MAF) is a precision surface polishing method. At present, most studies on planar MAF are focused on improving the surface roughness accuracy and the uniformity of roughness. In practical applications, the initial surface of the work piece is not only a rough surface, but also a flat surface without a uniform height. While the traditional processing method improves the surface roughness accuracy, the original surface is basically unchanged. In this paper, a processing method is studied. According to the uneven distribution of magnetic brushes, the reasonable distribution of processing speed and processing time can finally achieve the purpose of improving the surface flatness. At the same time, this paper analyzes the non-uniform characteristics of the magnetic pole and the magnetic brush itself, and verifies the effectiveness of the processing method through experiments.

Abstract: Ni–Co alloy coatings were electrodeposited at various cobalt amounts on pretreated steel substrates. The co-deposition phenomenon of Ni-Co alloys was described as anomalous behaviour. Different techniques including scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), X-ray diffraction (XRD) and potentiodynamic polarization were used to characterize the alloy coatings. EDX results showed that the Co content increase with the enhancing of Co amount. SEM images have shown that the increase of Co amount leads grain developing from large grain to branched grain form and that goes through spherical and pyramidal, this implies that the grain size of these alloy coatings is greatly affected by Co amount in the electrolyte baths. XRD patterns revealed that the phase structure of Ni–Co coatings is dramatically changed from fcc into hcp structure with the increase of Co amount. The electrochemical properties of Ni-Co alloy coatings evaluated in 3.5% NaCl solution reveal that Ni–34.32 wt.% Co alloy exhibits better corrosion resistance compared to pure Ni and other Ni–Co alloy coatings.

Abstract: The work investigates refractory metals (bulk W, W produced via plasma spraying, W-1% La₂O₃ and Mo) of interest as plasma facing materials in future nuclear fusion reactors. They have been irradiated by a single Nd:YAG laser pulse to simulate the effects of transient thermal loads of high energy occurring in a tokamak under operative conditions and then examined by SEM observations. In all the materials the laser pulse induces a crater in the central area of laser spot surrounded by a ridge due to movement of molten metal while in a more external area a network of cracks is observed. Diameter and depth of the crater, ablated volume and morphological features of the surrounding area exhibit differences depending on the specific metal, its physical and microstructural characteristics which affect vaporization, melting and heat propagation from the irradiated spot.

Abstract: These years, electronic devices and integrated circuits have a trend of miniaturization and integration with the rapid development of the information industry, higher requirements have been placed on the size, purity, and defect density of silicon wafers. More urgent demands have been placed on the mass production of electronic grade polysilicon. However, the research of electronic grade polysilicon in China is still in its infancy, it is far from meeting the requirements of mass production. This paper studies the influence of the single factor of reaction temperature on the yield of silicon, the surface morphology and power consumption of polysilicon under the certain conditions, which has some reference value for the production of electronic grade polysilicon.

Abstract: Magnetic force microscopy (MFM) and magnetometry, scanning electron microscopy (SEM) and atomic force microscopy (AFM) are used to study the magnetic and structural properties of the (Nd,Pr)-Fe–B and (Nd,Ho)-(Fe,Co)-B alloys. The alloys are synthesized using an arc or induction furnaces. The nanocrystalline state of the (Nd,Ho)-(Fe,Co)-B alloys is reached by two techniques, namely, melt spinning (MS) and severe plastic deformation (SPD). Hydrogenation and multistage treatment of (Nd,Ho)-(Fe,Co)-B alloys, which includes severe plastic deformation of melt-quenched ribbons and subsequent heat treatment, is also used. The surface morphology and domain structure of samples are studied. These pictures are used to interpret the observed magnetic hysteresis loops of the samples. It was found that multistage treatment allows one to obtain samples with higher values of coercivity due to the formation of a special microstructure with oval grain (the aspect ratio equal to ∼ 3).

Abstract: Acid hydrolysis method become one of the attention among researcher to produce high degree nanocellulose. Integration of sonication process was used to stir and mix particles in an element for different stages. This paper revealed the surface morphology and crystallinity index of two organic plant that were kenaf and oil palm nanocellulose. Characterization of the nanocellulose were identified by 2 techniques; (1) field emission scanning electron microscope (FESEM) that provides surface morphology and elemental information of the element, (2) x-ray diffraction (XRD) for phase identification of materials crystallinity. The result showed that the properties of nanocellulose increase after sonication method have been integrated.