Microstructure evolution of rare earth rich phase of rapidly solidified (RS) TiAl based alloys was investigated. The two rapid solidification techniques employed are melt spinning technique (MS) and Hammer and Anvil technique (HA). MS ribbons and HA foils were obtained in the experiment. The results demonstrate that with the increasing of cooling rates of TiAl based alloys great changes are taken place in the microstructures of rare earth rich phase, from scattering mainly on grain boundaries of as cast ingot to distributing homogeneously as very fine fibers or powders (nanometer grade) on the matrix. The fine paralleling second phase fibers in the HA foils are considered to be connected with γ/α 2 lamellar colonies. Selected area electronic diffraction (SAED) patterns of the rare earth rich phase isin accordance with that of intermetallic AlCe.
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