Synthesis of Ti3GeC2 Powders from Ti-Ge-TiC Mixtures by Pressureless Sintering

Abstract

Ti3GeC2 compound has excellent electrical and mechanical properties, which can be used as a potential reinforcement for Ag-based electrical contact materials. However, few reports have been addressed on the synthesis of its powders. The present study, therefore, presents a new route to fabricate high-purity Ti3GeC2 powders from Ti/Ge/TiC by pressureless sintering in vacuum. The influence of sintering temperature and Ge content on the powder purity was studied and the optimized conditions are found to be 1550 ℃ and Ti:Ge:TiC=1:1.1:2. In addition, the reaction path of Ti/Ge/TiC was revealed to be three steps: First, liquid Ge starts to react with Ti to form Ti5Ge3 compounds at around 1140 ℃; Then Ti5Ge3 consumes the liquid Ge and TiC to form Ti2GeC at around 1200 ℃; Finally, Ti2GeC transfers into Ti3GeC2 with the consumption of residual TiC. The present study lays the foundation for the subsequent applications of Ti3GeC2 powders in high performance composites.