Intermetallic Ti-47Al（in atomic fraction）and Ti-47Al-1W-0.5Si（in atomic fraction）alloys were produced by ISM method.Macro-and microstructure evolution was investigated by optical microscopy（OM）and scanning electron microscopy（SEM）.The macrostructure of ingot is composed of two different direction columnar grains due to the chilling of side wall and bottom in steel mould.The growth direction of the columnar grains is the preferred direction<0001>.The all lamellar orientation in columnar grains is perpendicular to the growth direction for the determined relationship of the solidstate phase transformation.A small amount of Si element added in the alloy can generate eutectic Ti5Si3 particle phase

and a little of B2 phase can be observed in Ti-47Al-1W-0.5Si alloy because of the addition of W as solid strengthening effects and the faster cooling rate.The addition of W and Si can refine the lamellar structure and improve mechanical properties of the Ti-47 Al alloy.The alloys have the high yield stress when the compression stress is parallel to the lamellar interface

and alloy crack is propagated alongα2/γlamellar interface

while alloys have the higher compression stress and strain when the stress is perpendicular to the lamellar interface

and fracture mode is characterized by crack crossingα2/γlamellar interface.