Papers by Author: Ye Han

Abstract: A novel wear resistant glass-ceramic coating system (based on SiO₂-B₂O₃-Al₂O₃ glass system) on iron based substrate was developed. Friction coefficient, wear rate and coefficient of thermal expansion of coating material were evaluated using suitable methods. The coating materials and the resultant coatings were characterized using differential thermal analysis (DTA), X-ray diffraction analysis (XRD) and Scanning Electron Microscope (SEM). XRD analysis of the coating materials showed presence of a number of microcrystal. SEM micrographs indicate strong chemical bonding at the iron-ceramic interface. The coating material showed perfect properties for protection the iron substrate from abrasion.

Abstract: Hybrid friction materials were manufactured with glass fiber, potassium titanate whisker and aramid fiber as reinforcement and the phenolic resin modified by lumbar pericarps oil as matrix material. The effects of load and sliding distance on friction and wear properties were studied by single variable experiments. The worn surfaces of the samples were studied by Scanning Electron Microscope (SEM). The results showed that friction coefficient and wear rate can be significantly increased when the load was increased up to 250N. The friction coefficient varied between 0.25 and 0.3 while the wear rate reduced to 0.49×10^-6 g/(N·m) in the sliding distance longer then 80m. Wear mechanism of samples were to be adhesive and abrasive wear.

Abstract: The Fe2O3-CaO-SiO2 glass ceramics were prepared by the method of quenching and controlled crystallisation. Differential thermal analysis, X-ray diffractometry and vibrating sample magnetometer were used to study the crystallisation and magnetic properties of Fe2O3-CaO-SiO2 glass ceramics. It was concluded that the main crystalline phases of glass ceramics during the process were Hematite, Iron Silico Oxide and Hedenbergite. The saturation magnetisation values (Ms) of glass ceramics varied between 108 emu•g-1 and 147 emu•g-1. The crystallisation of Hedenbergite lead to the high Hc value (~2000Oe).

Abstract: A theoretical procedure was developed with the aim of obtaining a rapid and accurate estimation of the degree of crystallization in glasses obtained from fly ash by measuring the dielectric constants. Compositions were prepared by melting the mixture of fly ashes, nucleators, fusing agents and clearing agents at 1500°C. Dielectric constant measurements were carried out by means of universal bridge. The results were compared with the degree of crystallization as evaluated by the method of density and showed a good agreement.