Papers by Author: Wei Ling Luan

Abstract: W@SiO₂ shielding composite microspheres were prepared by Sol-gel method for the first time. The component and morphology were investigated by Fourier transform infrared (FT-IR) spectra, Transmission electron microscopy (TEM) and Energy dispersive X-ray spectroscopy (EDX). The results reveal that polyvinylpyrrolidone (PVP) was introduced to the surface of tungsten nanoparticle successfully, and tungsten nanoparticle had been coated with silica. The appropriate hydrolysis reaction time is 3h, core-shell structure W@SiO₂ shielding composite microsphere can be synthesized and free silica decrease sharply. Core element and shell element of W@SiO₂ shielding composite microspheres were proved to be tungsten and silica respectively.

Abstract: A flask solvothermal method was firstly utilized to facile synthesize greigite Fe₃S₄ micro-crystals (MCs). By using iron nitrate, element sulfur as raw materials as well as oleylamine as the solvent, high yield of Fe₃S₄ MCs with hexahedron microstructure was obtained. In addition, it was found that it was easily to achieve transformation between Fe₃S₄ and Fe₇S₈ through changing reaction temperatures and iron-sulfur ratios. The several different morphologies of Fe₃S₄ MCs were obtained by using other sulfur sources. The synthetic approach demonstrated here could be of great potential for the controlled synthesis of other metal chalcogenides.

Abstract: Two types of joining specimens with and without Ni foil interlayer between 316L–SS bar have been prepared by diffusion bonding in a temperature range of 850- 1050°C, under a uniaxial pressure of 10MPa for 1hours. The relationship between the bonding parameters and the tensile strength of the joints at elevated temperature was studied. Optimized processing parameters were suggested based on the testing results. It was found that the introduction of the interlayer may reduce the room temperature strength but increase the high temperature strength. This was attributed to the transformation of Fe0.64Ni0.36 formed in bonding process into FeNi3 at high temperature.