Synthesis and sintering of Ti3GeC2 MAX phase powders

Abstract Ti 3 GeC 2 is one of the potential MAX phase compounds, for which, production and processing methods are yet to be optimized. There are very few reports on the synthesis of this compound, which are mostly in bulk form and contain large impurities. Present investigation attempts to synthesize Ti 3 GeC 2 powder with improved phase purity and to understand phase evolution sequences. Synthesis was characterized as a liquid-solid reaction process; initiated after melting of Ge particles. At low temperature (~1200 °C), yield was found to be very low, and the product had several intermetallics and carbides. At relatively higher temperature (at 1500 °C), the conversion was found to be very high and particles were mostly finer than 10 µm. Phase purity was further increased (over 96 wt%) during sintering stage, as observed through x-ray diffraction analysis where impurity peaks were very small. Ti 3 GeC 2 powder was found to exhibit poor densification behavior during pressureless sintering; however, it showed slow grain growth characteristics too, a highly desired feature for structural applications.