The effect of homogenizing treatment on the microstructures of two cast TiAl alloy with B addition was
investigated. It is found that homogenizing treatment at 1 370 /5min/ OQ and 1 150 /6 h/ AC can efficiently promote the elimination of B2 phase segregation,and the solution of bstabilizing elements to the matrix results in composition homogenization. The coarse as cast lamellar microstructures can be decomposed completely and transformed into fine near gmicrostructures through the above homogenizing treatment. The average grain size of fully lamellar microstructures is about 50 mm.