The isothermal aging behavior of Ti-5,8 and 10 mass%Fe alloys at 673K,
723K and 773K was investigated by resistivity and hardness measuremen
ts. X-ray diffractometry and transmission electron microscopy. The Tim
e-Temperature-Transformation diagram of the alloys was determined. In
Ti-5 mass%Fe and Ti-8 mass%Fe, the isothermal omega phase precipitated
by aging at all of the aging temperatures. Because the isothermal w p
hase did not precipitate by 773K aging in T-10mass%Fe, the upper tempe
rature limit for precipitation of isothermal omega phase in Ti-10mass%
Fe will situate between 723K and 773K. Incubation period prior to nucl
eation of a phase is shortened with elevating aging temperature. The i
nfluence of Fe content on the rime for nucleation of a phase was not c
lear. Only at 723K, resistivity and hardness of all specimens show sec
ond abrupt decrease by more than 600 ks aging, which suggests the prec
ipitation of TiFe.