Ti3Al based alloys with additions of Si, V, and V+Si were prepared in ingot form by argon arc co-melting and in the form of rapidly solidified ribbons by chill block melt spinning. Binary Ti3Al and ternary Ti3Al-Si arc-melted ingots showed equiaxed antiphase boundaries (APBs) in the alpha(2) (DO19) grain interiors with columnar APBs adjacent to the grain boundaries. In the melt spun ribbons, which undergo high cooling rates, three types of antiphase domain (APD) morphologies (fine, columnar, and coarse equiaxed APDs) were observed in any single alpha(2) grain. Addition of 15 at.%V to these alloys led to retention of the ordered beta (B2) phase with a relatively large antiphase domain size. (C) 2003 Kluwer Academic Publishers.