メカニカルアロイングによるTi₃SiC₂粉末の合成とその焼結体の機械的性質

抄録

The synthesis of Ti₃SiC₂ powder by mechanical alloying (MA) from elemental Ti, Si and C powders and pressureless sintering of the synthesized Ti₃SiC₂ powder were conducted. A high energy vibratory mill was used for the MA, in which the process parameters, such as milling time and ball size, were varied to investigate the MA conditions for Ti₃SiC₂ formation from the elemental powders. The Ti₃SiC₂ phase was first formed during the MA process using large-sized balls, i.e. with a large energy, but subsequently transformed gradually to an amorphous phase. When using small-sized balls, no Ti₃SiC₂ was formed during the MA although amorphous phase were obtained similarly as a fine powder. The MA-derived amorphous powders could be pressulessly sintered to dense Ti₃SiC₂-based ceramics containing less than 30% TiC_x as a secondary phase. The density, microstructure and mechanical properties of the sintered compacts were investigated with an emphasis on the effect of MA time.