High temperature mechanical properties evaluation of a #gamma# -TiAl base industrially developed intermetallic alloy

摘要

A new #gamma# -TiAl base cast alloy recently developed for creep properties maximization has been studied for evaluating high temperature mechanical properties. Tensile and creep behaviour are very good when compared with that of ensity corrected IN738LC, except for tensile ductility. Variable load creep testing does not affect sensibly creep resistance. Low cycle fatigue resistance is not strongly dependent on temperature and hold time. Tests performed in vacuum at 700 deg C show a reduction of fatigue crack growth rate when frequency is reduced. The observation of fatigue fracture surfaces has revealed the presence of lamellar propagation along crystallographic phanes. Areas with intergranular zones are observed when hold time is introduced.