SYNTHESIS OF TiAl+TiB_2 COMPOSITE AND-ITS THERMAL STABILITY

Synthesis process of a TiAl+TiB_2 composite from the elemental powders was studiedby means of differential scanning calorimetry and X-ray diffractometry.TiB_2 particlesmay form in TiAl matrix at temperature even below 700℃ owing to the exothermicreactions between Ti and Al powders.TiB_2 particles are very thermally stable,and theyalmost did not change in their relative amount,morphology and size after the synthesizedcomposite was remelted.In addition,the existence of TiB_2 particles has obvious refiningeffect in the as-cast microstructure of TiAl-base alloys.