Papers by Author: Yu Fang Shen

Abstract: This work focus on the effects of C vacancy on wetting of Fe to TiC/Fe at the cermet interfaces. We do the whole work using the first-principles density functional theories. The ideal work of adhesion of the pure interface is not big enough, comparing with the expeimental value. Our calculations suggest that the C vacancy at the interface is a very important factor for interface banding of TiC/Fe cermet composite. An adequate quantities of C vacancies at the interface can improve the wetting of TiC/Fe interfaces.

Abstract: First-principles plane-wave pseudopotential calculations of the electron structure and energetics of the interfaces of clean and Ni-doped TiC/Fe are reported. We predicted the atomic structure, bonding, and the interface binding energy of TiC(100)/Fe(100) and TiC(100)/Fe(110). By comparing the interface bonding energy and the total charge density distribution, the interface have priority to combine in TiC(100)/Fe(100) and TiC(100)/Fe(110) ways, where the former’s interface binding energy is higher. So the structure of TiC(100)/Fe(100) is more stable. The doped Ni atoms have preferential access to Fe-based body and form FeNi alloy, and enhance the interface bonding energy, thus effectively reducing the system energy of TiC(100)/Fe(100) and TiC(100)/Fe(110) interfaces, increasing the bonding strength and stability of interfaces of the composite materials.

Abstract: The paper presents a novel process for synthesis of ultrafine titanium carbide by reaction between TiOSO4 and Phenol-formaldehyde resins at different temperatures in the range of 1450°C–1500°C under argon cover for 1 hr. It was a new low-cost synthetic route for fabricating ultrafine TiC powders. The thermodynamic and reaction processes about phenolic resin’s cracking and reducing in the system of titanium oxide were studied. When the organic cracking reaction ended at 1000°C, amorphous carbon was provided by phenolic resin’s cracking. The grain size distribution of TiC synthesized from organic carbon was more narrower than that from inorganic carbon.