Research On The Synthesis Of Ti₂SnC And The Oriented Growth Of Ti₂SnC Grains

Ti₂SnC, a new ceramic material, has attracted much worldwide attention due to their unique properties of high electrical conductivity, machinability, self-lubricity and resistance to corrosion, etc.The main contents of this work are â‘  to comfirm the key parameters for synthesis of the high purity of Ti₂SnC powder by pressureless sintering the starting mixtures with different compositions and mole ratios; â‘¡ to synthesize the Ti₂SnC powder in low temperature and short time by mechanically activated low-temperature sintering technique(MALS); (3) to fabricate the high textured Ti₂SnC ceramic by controlling the oriented grain growth on a suitable template.The results show that the high purity of Ti₂SnC powder can be obtained by pressureless sintering a Ti/Sn/C mixture with a mole ratio of 2:1:1 at 1200℃ for 1 h under a vacuum atmosphere, and a Ti/Sn/TiC mixture with a mole ratio of 1:0.8:0.9 at 1200℃ for only 15min under a vacuum atmosphere, respectively.Using the technologies of XRD, SEM, EDS and DSC, etc, the characterization of the Ti₂SnC powder and the reaction mechanism for the formation of Ti₂SnC are systematically studied. Furthermore, the thermal stability and decomposing mechanism of Ti₂SnC in vacuum are also investigated. Ti₂SnC decomposes to Sn and TiC at 1250℃ under the vacuum atmosphere.Ti₂SnC has successfully been synthesized at a low temperature of 650℃ for 1 h under Ar atmosphere by using the MALS technology from the mechanically alloyed 2Ti/Sn/C mixture powders, which were milled for only 1 h. The synthesis temperature in the present study is lower about 600℃ than the reported temperature of 1250℃ using the conventional method to synthesize Ti₂SnC. The effect of the size of C particle in the Ti-Sn-C system on the formation of Ti₂SnC has also been studied.The oriented growth of the Ti₂SnC grains has been controlled on the C fiber template. Highly textured Ti₂SnC ceramic was fabricated at 1200℃ for 2h in a vacuum atmosphere by pressureless sintering the green sample consisted of the aligned C fibers which were infiltrated with a Ti-Sn slurry.