AbstractUnidirectional solidification has been employed to cast Ti–Al specimens containing TiAl lamellae separated by narrow Ti3Al lamellae. These lamellae were parallel and continuous throughout the specimens. Two different compositions, Ti–49·1 at.-%Al and Ti–50·8 at.-%Al, were used since the differing compositions resulted in different spacing between the lamellae, the latter displaying a wider spacing. Specimens were rolled with the plane of the lamellae parallel to and at 45°to the rolling plane in order to assess how ductility is affected by lamellar spacing and the direction of slip relative to the lamellae. Deformation was found to be highly anisotropic; ductility being greater when slip occurred in a direction parallel to the lamellae than when slip occurred in a direction at 45°to the lamellae. Reducing the width of the lamellae resulted in an improvement in ductility in both easy and difficult slip directions and this has been attributed to a reduction in the concentration of stress at lamellar boundaries.MST/1869