SYNTHESIS OF TiAl+TiB_2 COMPOSITE AND-ITS THERMAL STABILITY

摘要

Synthesis process of a TiAl+TiB2 composite from the elemental powders was studiedby means of differential scanning calorimetry and X-ray diffractometry.TiB2 particlesmay form in TiAl matrix at temperature even below 700℃ owing to the exothermicreactions between Ti and Al powders.TiB2 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 TiB2 particles has obvious refiningeffect in the as-cast microstructure of TiAl-base alloys.