Comparative study of the compression properties of TiAl matrix composites reinforced with nano-TiB_2 and nano-Ti_5Si_3 particles

摘要

The TiAl matrix composites reinforced with nano-TiB_2 and nano-Ti_5Si_3 particles were successfully fabricated by the in situ method of combustion synthesis and hot press consolidation. The sizes of the synthesized TiB_2 and Ti_5Si_3 particles are about 30-50 nm and 60-80 nm, respectively. The synthesized nano-TiB_2 particles could significantly enhance the ultimate compression strength (σ_(true)~(UCS)) of the TiAl alloy, and the σ_(true)~(UCS) increases with the increase in the TiB_2 content. The average σ_(true)~(UCS) of the 6 vol% TiB_2/ TiAl composite is 477 MPa higher than that of the TiAl alloy. The synthesized nano-Ti_5Si_3 particles could improve the strength and ductility of the TiAl alloy simultaneously, and the σ_(true)~(UCS) and fracture strain (ε_(true)~f) increase first and then decrease with the increase in the Ti5Sij content. The average σ_(true)~(UCS) of the 4 vol% Ti_5Si_3/TiAl composite is 171 MPa higher than that of the TiAl alloy, and the average ε_(true)~f increases from 17.3% to 20.9%.