Papers by Author: Bao Yan Liang

Abstract: ZnO nanometer materials were synthesized by microwave reaction from ZnO micrometer powders with different C aids. Effect of C style on the morphology of ZnO products was studied. The result show that ZnO nanometer materials can not be formed by using directly high temperature evaporation from ZnO micrometer powders without C aids. Fine ZnO nanometer crystals can be obtained by using carbon black as aids. In this sample, most ZnO grains were nanometer particles with a size of about 100nm. And a small amount of ZnO grains were short rods with a length of 1~2μm and a average diameter of 100nm. Amounts of short columnar and long zigzag ZnO crystals can be obtained by using graphite as aids. One effect mechanism of ZnO crystalline was proposed. ZnO reacted C to form CO and CO₂ gas. Concentration of CO/CO2 directly effects the morphology of ZnO in the products.

Abstract: An oxide-alumina-silica coating which would to improve the oxidation resistance of carbon fibers was prepared by sol-gel method. XRD and SEM were used to characterize the surface appearance and phase transition about the carbon fibers with oxide-alumina-silica coating. The oxidation resistance of carbon fibers was also analyzed with the DSC-TG and the isothermal oxidation experiment. It was shown that the antioxidant properties of the carbon fibers with oxide-alumina-silica coating improved significantly. The concentration of precursor sol had an influence on the coating of carbon fibers and the antioxidant properties of the carbon fibers with oxide alumina silica coating increased 300°C compared to uncoated ones.

Abstract: The Ti3AlC2 was synthesized by self-propagating high-temperature sintering (SHS) using 3Ti/Al/2C powders as raw materials. Si or Sn was added to the raw materials in order to improve the synthesis reaction of Ti3AlC2. The result showed that the majority compounds were Ti3AlC2 and TiC in the synthesized sample. The content of Ti3AlC2 in the sample was approximate 59%. Si or Sn additives improved the synthesis of Ti3AlC2 obviously and the effect of Si additive in the reaction was much better than that of Sn. For raw materials of 3Ti/Al/2C/0.3Si, the content of Ti3AlC2 in the sample reached the maximum value of 93%.

Abstract: Titanium carbonitride, V(C, N) has been prepared by combustion synthesis from V powders and a carbon-nitrogen precursor. The phase composition of the sample was investigated by X-ray diffraction. The scanning electron microscopy image indicates that the average size of the obtained V(C, N) grains was 1µm.

Abstract: SiC/Ti3SiC2/TiC composites were fabricated by means of pressureless sintering using the 3TiC/2.2Si/0.2Al as raw materials. At the temperatures from 1000°C to 1200 °C, the main phase of the composite synthesized was Ti3SiC2. At the same time, there was a small amount of TiC and SiC existing. The composite had loose microstructure. At the temperature of 1300 °C, the TiC and Ti3SiC2 were the primary phases. And the SiC was the second phase. The SEM images showed that there were two kinds of microstructures in the composite. One was the Ti3SiC2 and the TiC platelets on its surface, another one was the TiC and the SiC equixed grains in its interior.