メカニカルアロイング法によるTi_5Si_3金属間化合物の合成と加圧焼結 Synthesis of Ti_5Si_3 Intermetallic Compound by Mechanical alloying and Pressure Sintering
Mechanical alloying (MA) of Ti-37.5mol%Si composition powder mixture (stoichiometric composition of Ti<SUB>5</SUB>Si<SUB>3</SUB> intermetallic compound) and synthesis of Ti-silicides by milling and heat treatment of MAed powders were investigated. The formation of TiSi and TiSi<SUB>2</SUB> phase were observed by milling over 540ks, but stoichiometric phase, Ti<SUB>5</SUB>Si<SUB>3</SUB>, was not formed only by milling. Fully MAed powder (more than 1800ks) changed to almost Ti<SUB>5</SUB>Si<SUB>3</SUB> single phase after DTA runs up to 1173K. On the other hand, in the case of short period MAed powders, TiSi and TiSi<SUB>2</SUB> were also formed during DTA runs in addition to the Ti<SUB>5</SUB>Si<SUB>3</SUB>.<BR>We tried to make a dense compact using the vacuum hot pressing technique. Relative density of hot pressed compact was 99.7% of theoretical density. The hot pressed compact showed high micro-Vickers hardness more than HV 1300 and K<SUB>IC</SUB> value of 1.46MPa⋅m<SUP>1/2</SUP>. Fracture toughness of the compact exceeded the value of arc melted material, 1.19MPa.m<SUP>1/2</SUP>.
粉体および粉末冶金 45(10), 1000-1006, 1998-10-15
Japan Society of Powder and Powder Metallurgy