Xinli Liu

Pore Formation Process of Porous Ti3SiC2 Fabricated by Reactive Sintering

Porous Ti3SiC2 was fabricated with high purity, 99.4 vol %, through reactive sintering of titanium hydride (TiH2), silicon (Si) and graphite (C) elemental powders. The reaction procedures and the pore structure evolution during the sintering process were systematically studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). Our results show that the formation of Ti3SiC2 from TiH2/Si/C powders experienced the following steps: firstly, TiH2 decomposed into Ti; secondly, TiC and Ti5Si3 intermediate phases were generated; finally, Ti3SiC2 was produced through the reaction of TiC, Ti5Si3 and Si. The pores formed in the synthesis procedure of porous Ti3SiC2 ceramics are derived from the following aspects: interstitial pores left during the pressing procedure; pores formed because of the TiH2 decomposition; pores formed through the reactions between Ti and Si and Ti and C powders; and the pores produced accompanying the final phase synthesized during the high temperature sintering process.

Direct separation of arsenic and antimony oxides by high-temperature filtration with porous FeAl intermetallic

A temperature-controlled selective filtration technology for synchronous removal of arsenic and recovery of antimony from the fume produced from reduction smelting process of lead anode slimes was proposed. The chromium (Cr) alloyed FeAl intermetallic with an asymmetric pore structure was developed as the high-temperature filter material after evaluating its corrosive resistance, structural stability and mechanical properties. The results showed that porous FeAl alloyed with 20wt.% Cr had a long term stability in a high-temperature sulfide-bearing environment. The separation of arsenic and antimony trioxides was realized principally based on their disparate saturated vapor pressures at specific temperature ranges and the asymmetric membrane of FeAl filter elements with a mean pore size of 1.8μm. Pilot-scale filtration tests showed that the direct separation of arsenic and antimony can be achieved by a one-step or two-step filtration process. A higher removal percentage of arsenic can reach 92.24% at the expense of 6∼7% loss of antimony in the two-step filtration process at 500∼550°C and 300∼400°C. The FeAl filters had still good permeable and mechanical properties with 1041h of uninterrupted service, which indicates the feasibility of this high-temperature filtration technology.

Development and characterization of microporous Ti3SiC2 ceramic membranes for filtration of microorganisms

A novel porous filter material was fabricated by element reactive synthesis method. The synthesized porous Ti3SiC2 membrane material presents a microstructure of both large substrate pores and small membrane pores, indicating large filtration flux and high filtration accuracy simultaneously. Microorganism filtration properties of the porous Ti3SiC2 membrane material were investigated by filtering the Escherichia coli suspension, which demonstrates excellent performance of the porous materials on filtration.

Factors affecting the property of porous Ti3SiC2 metal ceramic fabricated through pressureless sintering

Abstract In this paper, micrometer-sized porous Ti3SiC2 metal ceramic was fabricated through a reactive synthesis method using titanium hydride, silicon and graphite elemental powders. The factors including raw powders, pressing pressure, sintering procedure affecting the purity and the pore property of porous Ti3SiC2 were systematically studied. The results indicate that the purity, pore property including maximum pore size and porosity can be effectively controlled by adjusting the synthesis parameters.

Corrosion behavior of porous Ti 3 SiC 2 in nitric acid and aqua regia

Abstract Porous Ti3SiC2 with high purity was synthesized using TiH2, Si and C powders with mole ratio of Ti to Si to C being 3:1.2:2 by reactive synthesis method. The corrosion behaviors of porous Ti3SiC2 in nitric acid and aqua regia were investigated by immersing test. Scanning electron microscope (SEM), X-ray diffractometer (XRD), energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) were used to analyze the morphology, compositions and element contents of the samples before and after corrosion to determine the corrosion product and corrosion mechanism. The mass loss values of porous Ti3SiC2 are 26.9 and 132.5 μg/cm2, respectively after immersing in nitric acid and aqua regia for 600 h. The results indicate that Ti3SiC2 transforms to Ti5Si3 which has better corrosion resistance in nitric acid and aqua regia with mass loss values of 9.34 and 7.06 μg/cm2 under the same immersing time, respectively. The dramatic dissolution of porous Ti3SiC2 in the acids is due to its special microstructure.