Papers by Keyword: Surface Morphology

Abstract: Oven drying and microwave drying processes for GeO₂ after hydrolysis and filtration of GeCl₄ were performed, and then the polymorphs, surface morphology and chemical composition, etc. of GeO₂ were analyzed. The influence of microwave power and material thickness to GeO₂ moisture removal rate was researched in a single-factor-based test. The gained optimum process parameters for microwave drying GeO₂ are as below: microwave power is 400~550 W, material thickness for each time is 30~40 mm, and drying time for 1 kg GeO₂ is 36.67~40.00 mins. The results show that through the two processes, they can both gain GeO₂-06 products meeting national standard, and compare with them to obtain that microwave drying has the advantages of high efficiency, low energy consumption, no caking, etc.

Abstract: The influence of Zwitterionic - propanesulfonate surfactant on the surface properties such as surface roughness, surface morphology and microhardness of Ni-B coatings using electroless alkaline bath was reported in this paper. Ni-B deposits obtained from nickel chloride as the source of nickel and borohydride as the reducing agent at a pH of 11 and 12 and temperature 85 ± 2 ^OC. This study reveals that the Ni – B coatings were clearly influenced by the addition of surfactant propanesulfonate on surface roughness and surface morphology. Electroless nickel (EN) - B coatings with addition of surfactant has changed the surface morphology from non-smooth nodular appearance to a smooth surface with average roughness value 1.4μm, which is less than the R_a value of without surfactant 1.98μm. The hardness of the deposit increased with lesser concentration of the surfactant when compared to without surfactant addition. Surface morphology and composition of the Ni–B coatings was analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD).

Abstract: The aim of the present investigation is to study the formation of electroless Ni-B-P alloy coatings and structural and morphological characterization of various coatings with different boron and phosphorous content. An alkaline plating bath with nickel chloride hexahydrate as the source of nickel ions and sodium borohydride and sodium hypophosphite as reducing agents were used for the formation of electroless Ni-B-P alloy coatings. The influence of changes in the concentrations of the reducing agents in the electroless plating bath on the chemical composition, structural and morphological characteristics of the coatings were studied. Scanning electron microscopic studies revealed that the surface morphology of Ni-B-P alloy coatings changed from corn cob-like structure to cauliflower-like structure with increasing borohydride concentration in electroless plating bath, whereas increase in hypophosphite concentration favoured sideway growth, thereby decreased the surface roughness of the Ni-B-P alloy coatings. The peak broadening in the X-Ray Diffraction profiles indicates the large reduction in the crystallite size of the electroless Ni-B-P alloy coatings with increasing boron content in the coating (i.e. for higher borohydride concentration in the plating bath).

Abstract: The mechanics characteristics of the rock are mainly subjected by the joint and the fractures of the rock mass. For the joint, the surface morphology is especially the dominant influence factor. In order to describe the nature physics of rock surface, the surface morphology embarked on a fractured granite rock is described. And use the fractal dimension to calculate the volume of covering rock fracture surface, the relationship between fractal dimension and physical characteristics of rock surface.

Abstract: The surface morphology and structure of the cubic stoichiometric spinel LiMn₂O₄ powder prepared by microwave heating were examined using X-ray diffraction, scanning electron microscopy and transmittance electron microcopy. It is shown that the surface morphology of LiMn₂O₄ particle changed with increasing preparing temperature, while the crystal structure kept unchanged. Novel nanostructured morphologies including nanorods and nanowhiskers were formed under appropriate synthesis conditions. The growth mechanism of the nanostructured morphology of spinel LiMn₂O₄ was discussed in accordance with period bonding chains (PBCs) theory.

Abstract: Multiscale simulations using the quasicontinuum (QC) method with the embedded-atom method (EAM) potential are performed to investigate the process of nanocontact including sliding and subsequent withdrawal between Ni tip and Au substrate. The multiscale model reveals that deformation twinning in Au substrate is induced not only by the sheer stress but also by the adhesive stress. Combining with the generalized planar fault energy (GPF) curve of Au, the underlying formation mechanism of deformation twinning is studied in detail. During the withdrawal process, the dislocation degeneration and the vacancy evolution are observed.

Abstract: The effect of compression storage on structure and surface morphology of silicone rubber in silicone rubber-stainless steel interfacial system was studied in the paper by means of ATR-FTIR, Raman spectrums, XPS spectrums and SEM. FTIR and Raman spectrums analysis indicated that no chemical change in silicone rubber was found during compression storage. XPS spectrums analysis indicated that there maybe surface chemical reaction took place during compression storage. SEM analysis indicated that the number and diameter of the open holes and microholes on the surface of samples decreased significantly with storage period, which hindered air to enter the interface when pressurized state was removed, and was beneficial for vacuum adsorption.

Abstract: Through the composite electrodeposition process of preparation of Ni - TiN nanocomposite plating, laser processing on its surface strengthening processing, using SEM, XRD, scratches on the surface morphology and composition were analyzed. Amount of nanoparticles suspension in plating solution is studied for nanocomposite coating under dry friction condition wear resistance; After laser hardening on the surface of a coating the hardness, wear resistance test, and optimize the electrical parameters. Ultrasonic electric sediments compared with ordinary mechanical stirring electric sediments, the surface is more meticulous, uniform, less pinhole; Laser assisted processing, makes up the defect of the general nickel plating adhesion strength is poorer, to some extent, to expand the application range of nickel plating.

Abstract: This paper presents a new procedure to estimate the material removal (MR) in such conditions or operations where small amount of material or wear occur. The monitoring of material removal is essential to understand the machining mechanisms of several processes such as super finishing ones. For example the study of some mass finishing (MF) operations, i. e. the barrel finishing (BF) and the spindle finishing (SF), have been always limited by the difficulty to measure the local surface modification. Thus there is no knowledge about the relationship between process parameters and obtainable surface quality. The procedure is based on profilometer measurements typically used to characterized local surface morphology. An algorithm automatically finds the most representative peak of the profile. The comparison between the Abbot-Firestone curves, related to peaks achieved in different condition, permits to measure the volume of material removed by the operation. This method overcomes the well-known problem to repositioning the instrument in the same place when the part is moved from machining process to measurement one. In the case of BF, experimental demonstrated the reliability of this methodology to provide the evolution of material removed as a function of working time. Moreover the graphical plot of the representative peak at different times gave important information about machining mechanism. In particular it allowed to verify assumptions regarding the plastic deformation and the peak cutting which takes place.

Abstract: ZnO-SiO₂ nanostructures were grown on both bare Si and Pt-coated Si substrates via chemical bath deposition (CBD). The grown nanostructures were characterized using Scanning Electron Microscope with Energy Dispersive X-ray Spectroscopy (SEM-EDS), Fourier Transform Infrared (FTIR) measurement and Ultraviolet-Visible (UV-Vis) absorption spectroscopy. Surface morphology results revealed that Pt-coated Si substrate have promoted the growth of ZnO-SiO₂ nanostructures by providing more active sites for nucleation thus formation ZnO-SiO₂ nanostructures were observed. It is believed that SiO₂ will adhere to the non-polar sides of the grown ZnO nanostructures. This result is manifested in the FTIR spectra which showed a pronounced peak corresponding to ZnO-SiO₂ grown on bare Si suggesting that more Si-O bonds are present. However, Pt-coating did not significantly affect the band gap of the grown ZnO-SiO₂ nanostructures.