Papers by Keyword: Surface Morphology

Abstract: The anisotropic silicon etching characteristics of TMAH(tetramethyl ammonium hydroxide)+Triton at near the boiling point were investigated. The etch rate of Si {100}, the convex corners, and the roughness of the etched surface contact with the fabrication of bulk microstructures and thus micromechanical devices in silicon. This study presents that the etch rate of Si {100} in 25 wt.% TMAH with 0.1% Triton at near boiling point (112°C) is 1.37μm/min, it is three times higher than it at 80°C. The surface roughness and convex corners of Si {100} after etching at different temperature were investigated by optical microscope, scanning electron microscope (SEM) and atomic force microscope (AFM). The etching rate and smoothness of an etched surface can be improved simultaneously at near boiling point, meanwhile, the undercutting on convex corner should be accepted.

Abstract: Band saws machine is the most efficient metal cutting machine. By losing less material, material qualitative, having big saw range and having low cutting costs are superiority of band saws. Band saws are acting with most long route and more limited support point in all cutting tools. In band sawing machine, band saws and structure are easy to produce vibration. Affect cutting life, costs of band saws and material surface topography. So this study focuses on analyzing what is vibration cause of band saws by vibration source and establishes the relationship between band saws natural frequency along and change cutting condition. In this research use the C-430GNC band saws machine, and use S45C material for cutting test. Accelerometers are used with a measurement system to capture sawing vibration data. By the fast Fourier transform to analyze spectrogram transform in order to identified characteristic spectrums, and find out vibration feature with band sawing operating conditions and unusual evens came from wear of blade. Minimum cutting vibration and best surface topography were compared to find out the best cutting condition.

Abstract: ZnO doped Al₂O₃ and ZrO₂ (ZAZO) thin films were deposited by the radio frequency magnetron sputtering on substrate temperature with 100°C, 150°C, 200°C, 250°C and 300°C. The surface morphology and electrical properties of the films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and four-probe tester. The results showed that the substrate temperature obviously influenced the grain size of ZAZO films. The ZnO thin film had the largest crystallization orientation for the (002) peak and the smallest FWHM value at substrate temperature of 250°C. As the temperature increasing, the resistance of films gradually decreased till reaching a minimum at 250°C and then rised. Due to the increasing of Al and Zr concentrations into ZnO lattice, the Al ions created an abundance number of free electrons in the ZnO lattice, and in turn, the electrical conductivity increased. In addition, the improvement of film in the crystalline state results in the film resistivity decreases.

Abstract: In the paper the SiO₂CuO_x and SiO₂(CuO_xSnO_y) thin films were deposited from the alcoholic solutions employing the sol-gel technique. The films were characterized by means of SEM (scanning electron microscopy) and 2p x-ray photoelectron spectroscopy (XPS). The SEM studies found the grain shape changes from flower-like to regular shaped inorganic agglomerates as result of adding the SnCl₄ into the sol. The X-ray photoelectron spectroscopy (XPS) studies showed the presence both CuO and CuO₂ phases and formation of a double CuSiO₃ oxide phase.

Abstract: A new fluorinated acrylate terpolymer hydrophobic polymer was prepared by emulsifier-free inverse microemulsion polymerization using methyl methacrylate (MMA) and hexafluorobutyl acrylate (HFBA) as monomers, and methyl polyethylene glycol methacrylate (MPEGMA) as polymerizable emulsifier. Membrane properties were characterized by means of FT-IR, SEM and Contact Angle Meter. The effect of fluorinated monomer content, water content in the inverse precursor microemulsion on the surface morphologies and hydrophobicity of the polymer film was mainly discussed. Morphological studies of the fluorinated polyacrylate polymers by SEM showed that discrete granular microstructures were obtained from precursor microemulsion with higher water content. On the other hand, smooth and continuous surface morphologies were found with lower water content. Contact angle revealed that the fluorine preferentially enriched at the film-air interface and more hydrophobic that the film-glass interface. The amount of HFBA had significantly effects on the film properties. The water contact angle of the film-air interface increased as the amount of HFBA increased from 0 ml to 4 ml and then remained almost unchangeable. The film formed from the fluorinated polyacrylate polymer with higher water content in the precursor microemulsion exhibited better hydrophobicity in comparison with the film formed from the fluorinated polyacrylate polymer with the lower water content, and it confirmed that rough surface have high water contact angles.

Abstract: In this work the effect of substrate and vaporization temperatures on the structural parameters (sizes of coherent scattering region, values of strain), phase and chemical composition, surface morphology of Co films is revealed. Co films were deposited on Si (100) substrates by Metal-organic chemical vapor deposition using the diiminate complex Co (N’acN’ac)₂ as a precursor. The sizes of coherent scattering region, values of strain and phase composition of Co films were determined by the X-ray diffraction analysis. The chemical composition was identified by the Energy-dispersive X-ray spectroscopy. The surface morphology of Co films was investigated by scanning electron microscope. It is found that the variation of deposition conditions allows us widely to change structural parameters and chemical composition of Co films.

Abstract: The effects of nano-diamond seeds on the performance of diamond-like carbon (DLC) films were investigated. In this study, the high uniform DLC films were deposited on substrates seeded with nano-diamond by using a magnetron sputtering system. Then, the effects of nano-diamond seeds on DLC films were determined. Raman spectroscopy revealed a decrease of sp3 fraction due to the introduction of nano-diamond seeds. Atomic force microscope (AFM) observed all samples have an average root mean square (RMS) roughness of 1.8 nm. Scanning electron microscopy (SEM) displayed that a large number of small size conical hillock geometrical anomalies can be caused by nano-diamond seeds. Indentation tests revealed that nano-diamond seeds can enhance the hardness of DLC films, whose hardness range is from 28.3 GPa to 32.1 GPa in this work.

Abstract: Diamond-like carbon (DLC) film has remarkable physical, mechanical, biomedical and tribological properties that make it attractive material for numerous industrial applications needs of advanced mechanical systems. In this study, deposition process of DLC films on Si (100) are performed by direct-current (DC) magnetron sputtering method. The effects of interlayer on the compositions, structures and mechanical properties of DLC films are studied. The scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies reveal the creation of high uniform surface morphology and low roughness DLC films with SiN_x interlayer. For comparison, DLC films with different interlayers are also grown. The Raman spectra are analyzed in order to characterize the film compositions. Indentation test was performed to value the mechanical properties of DLC films. Raman, SEM, and AFM analyses are correlated with the mechanical properties of the DLC films.

Abstract: Ni-doped copper nitride films have been prepared by co-sputtering of Ni and Cu targets. The addition of Ni to Cu₃N films reduced the intensity of the (111) diffraction peak, and lead a little angular shifts of the peaks. The films showed a large difference in reflectance in the infrared and visible before and after thermal decomposition, which is applicable to optical recording media. The films change from a semiconductor to a conductor with the increased ratio of Ni in Cu₃N films.

Abstract: Sustainable manufacturing in most developed countries is one of principal goals in today manufacturing industry. The reduction in use of oil-based CLFs is most ecologically important task of machining processes. The paper presents the contribution in engineering of surfaces particularly in surface morphology of Stainless Steels. The objective of the investigation was to determine the surface texture of duplex stainless steel after turning with coated carbide tool point. The investigation included geometrical parameters of Surface Integrity for different cutting parameters in dry turning process of duplex stainless steel.