Shengfang Shi 교수

Abstract Al 2 O 3 /Ti composites containing 0‐30 vol% dispersed fine Ti particles were fabricated using a hot‐press sintering method at 1500°C from mixtures of Al 2 O 3 and TiH 2 powders. During sintering, TiH 2 decomposed to form metallic Ti. The effects of the Ti content on the mechanical and electrical properties of the composites were then investigated. No Ti‐Al intermetallic compounds were detected by X‐ray diffraction, and energy‐dispersive X‐ray spectroscopy indicated the presence of Al‐T

Abstract We demonstrated for the first time the room‐temperature crack healing in ceramic‐based composites. For this purpose, 20 and 30 vol% of fine titanium metal (Ti) were homogeneously dispersed in electrically insulating alumina (Al 2 O 3 ) ceramic to obtain composites that exhibited excellent electrical conductivity. Electrochemical anodization at room temperature was used to successfully heal cracks induced in the Al 2 O 3 /Ti composites and recover their fracture strength and reliability.

Abstract To further improve the mechanical performance and reduce the percolation threshold by controlling microstructures, Al 2 O 3 ‐TiC composites containing 0‐20 vol% TiC were fabricated via in situ reaction synthesis. Graphite (ATC) and carbon nanotubes (ATCT) were used as carbon sources. The composites were also fabricated via a conventional process using a TiC starting powder (AT). X‐ray diffraction analysis and scanning electron microscopy observation results indicated successful fabricat

Abstract This study addressed novel multiphase composite of Al 2 O 3 /Ti/TiC that exhibited enhanced fracture toughness and room‐temperature crack‐healing function. Al 2 O 3 /Ti/TiC composites were fabricated through hot‐press sintering of CNT, TiH 2, and Al 2 O 3 mixed powders, where the TiC was in‐situ formed by reaction of CNT and Ti. The effects of CNT (TiC) content on mechanical and electrical properties were studied. Electrochemical anodization process at room temperature was attempted to

Abstract This work discusses the reinforcement effect of elongated CeAl 11 O 18 phase on multifunctional Al 2 O 3 /Ti composites by adding CeO 2 to inhibit interfacial reaction and strengthen interface for inducing optimized performances. For this purpose, Al 2 O 3 /Ti composite with different contents of CeO 2 was fabricated and the microstructure, mechanical and electrical properties were studied. Results indicated that after CeO 2 was added, elongated CeAl 11 O 18 phase was formed within thes

In this work, a potentially novel ceramic-based composite was developed for photocatalytic activity. Hot-press sintered Al2O3/Ti composites containing 20 vol.% of metallic Ti were treated with NaOH and heated to generate a nanometer-scale structure to induce an active surface layer for photocatalytic activity. Because NaOH treatment does not affect Al2O3 ceramics, to form a nano-structured titania layer over the entire surface of a composite whose surface contains both Al2O3 and Ti, strict contr

Abstract This work aims to enhance the fracture toughness of brittle Al 2 O 3 ceramics and apply insulated Al 2 O 3 ceramics with electrical conductivity by dispersing second tungsten (W) metal particles. In order to investigate the effects of W dispersion on mechanical and electrical properties, Al 2 O 3 –W composites with various amounts of W (ranging from 5 vol% to 20 vol%) were fabricated by the hot‐press sintering method at various sintering temperatures. Microstructure analysis revealed su

Abstract This work investigates the effects of content ratio Co 3+ /Co 2+ on piezoelectric properties of lead‐free Ba 0.88 Ca 0.12 Zr 0.12 Ti 0.88 O 3 (BCZT) ceramics. For this purpose, 0.10 wt% Co ions using a CoO powder doped BCZT ceramics were sintered under various atmospheres (ranging from pure nitrogen to 100 vol% oxygen concentration) to vary the ratio value Co 3+ /Co 2+ . X‐ray photoelectron spectroscopy analysis revealed the coexistence of Co 3+ and Co 2+ for oxygen concentration below