抄録
The influences of input energy density determined by the processing parameters on structural integrity and microstructure of
b-containing Ti-44Al-4Cr alloy rods fabricated by electron beam melting process were investigated. We found that it is important to
control the input energy density to obtain the rods with good dimensional accuracy. Moreover, we also found that the microstructure
of the rods depends strongly on the input energy density. The rods fabricated at higher energy densities show a uniform α 2 /β/γ
mixed structure. On the other hand, ultrafine α 2 /γ lamellar grains and β/γ cells which are discontinuously precipitated at the grain
boundary of the lamellar grains can be seen at lower energy densities. The unique ultrafine lamellar grains are originated from the
massive a grains formed upon rapid cooling. The strength and ductility of the alloys are closely related to the volume fractions of the
ultrafine lamellar grain and the β/γ cells, respectively.
