Papers by Author: Kai Li

Abstract: SiO2-SiC composite particles were prepared using a sol-gel process. BaTiO3 powders were synthesize through solid-state reaction. They were mixed as microwave absorbents with Fe3O4 powders to obtain the complex absorption. Epoxide resin (EP) was used as matrix and solidified with the mixtures. The techniques of DSC-TG, XRD were used to characterize the composite particles and the obtained compacts. A vector network analyzer was used to measure the reflectivity of the SiO2-SiC-based composites. The effects of the aborbents’ contents on the reflection of the microwave absorption materials were disscussed. It was found that SiO2-SiC composites could be prepared using sol-gel process and BaTiO3 powders could be synthesize through solid-state reaction. The results indicated that SiO2-SiC composite is contribute to absorb microwave, where SiO2-SiC: BaTiO3: Fe3O4 = 6:2:2 (vol %), the frequency region in which the maximum reflectivity is more than -10 dB is 5.4-7.6 GHz.

Abstract: SiC particulate-reinforced Fe composites were prepared by a powder metallurgy (PM) and conventional atmospheric sintering method. X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques were used to characterize the obtained composites. The coating layer of Cu on SiC particles can suppress the reaction between SiC and Fe until 1250oC. The maximum microhardness of 283 Hv appears at near 1250oC. Substantial reaction occurs at above 1250oC, which leads to the deterioration in the microstructure and related properties. The inter-metallic compounds of FeSi or Fe2Si were detected which contributed to the enhancement of the interface between SiC and Fe.