PLASTIC-DEFORMATION OF SINGLE-CRYSTALS OF TI3AL WITH DO19 STRUCTURE

Single crystals have been successfully grown by floating-zone melting of an intermetallic compound Ti3Al which has the beta- to alpha-phase transformation at about 1453 K. Single-crystal specimens of three major orientations were compressed in a temperature range from 300 to 1273 K and examined for the deformation characteristics of the three slip modes, namely {11BAR00}<11BAR20> prism slip, (0001)<11BAR20> basal slip and {112BAR2}<11BAR23> pyramidal slip. Deformation morphology and dislocation arrangements were studied by optical microscopy and transmission electron microscopy respectively. The deformation behaviour and dislocation arrangements, which are very different from those reported on polycrystalline materials, are presented and discussed.