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- Kero, Ida, et al.
(author)
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Preparation and firing of a TiC/Si powder mixture
- 2009
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In: 5th International EEIGM/AMASE/FORGEMAT Conference on Advanced Materials Research. - Bristol : IOP Publishing Ltd. ; 5, s. 012016-
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Conference paper (peer-reviewed)abstract
- This paper describes how the preparation and heat treatment of TiC/Si powders influences the phase reactions during firing. The powders are prepared by milling and some effects of powder preparation are discussed. A solid state displacement reaction according to: 3TiC + 2Si → Ti3SiC2 + SiC is a priori expected to take place during heat treatment. The firing procedure is investigated with respect to the effect of heat treatment time and temperature on the phases produced, especially Ti3SiC2. Samples were heat treated in a graphite lined furnace. Heat treated samples are analysed by x-ray diffraction, scanning electron microscope and energy dispersive spectroscopy. Ti3SiC2, TiC and SiC are dominant in the final products. The highest amount of Ti3SiC2 is achieved for short holding times (2-4 hours) at high temperatures (1350-1400°C). Ti3SiC2 appears to decompose at elevated temperatures or extended times, through a Ti3SiC2 → TiC + Si(g) type reaction. The activation energy of Ti3SiC2 phase formation is determined to be 289 kJ/mol, using the Mehl-Avrami-Johnson model.
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| 2. |
- Kero, Ida, et al.
(author)
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Synthesis of Ti3SiC2 by reaction of TiC and Si powders
- 2009
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In: Mechanical properties and processing of ceramic binary, ternary and composite systems. - Hoboken, NJ : John Wiley & Sons. - 9780470344927 ; , s. 21-30
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Conference paper (peer-reviewed)abstract
- The MAX phase Ti3SiC2 has been synthesized from starting powder mixtures which do not include pure titanium. The presence of pure titanium in a powder is problematic because of its oxidizing, and in the form of a finely divided powder, explosive nature. The aim of this study was to evaluate the synthesis of bulk polycrystalline samples of Ti3SiC2 from a starting powder mixture which is more suited for large scale production. Titanium silicon carbide MAX phase was synthesized by pressureless sintering of ball milled TiC and Si powders of six different compositions. The sintering reactions were evaluated in situ by dilatometer analysis under flowing argon gas. The as-sintered samples were evaluated using mainly x-ray diffraction (XRD) analysis. This study showed that titanium carbide, silicon carbide and titanium disilicide were present as intermediate or secondary phases in the samples.Our results indicate that TiSi2 is an intermediate phase to the formation of Ti3SiC2 when excess Si is present. The excess of silicon also proved beneficial for the synthesis of the MAX phase and there is a Si content which is optimal with respect to the maximum MAX phase content of the final product. The Ti3SiC2 was found to decompose into TiC and gaseous Si at high temperatures.
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