Mechanisms contributing to the pinning of ordinary dislocations in γ-TiAl

Properties of ordinary dislocations and related debris are investigated in single crystals of γ-TiAl deformed in single slip at 20°C and 400°C. Typical of this temperature range are prismatic loops isolated or belonging to arrays, together with multipoles. The interaction of these with mobile ordinary dislocations generates various configurations including trailing-like hairpins. Certain features are consistent with an extrinsic origin for point pinning.