Static strain ageing of L1 sub 2 Al sub 3 Ti-based alloys

The Al sub 3 Ti-based intermetallics stabilized in the L1 sub 2 structure by additions of transition metals are known to show stress-strain serrations during high temperature deformation. The dislocation pinning phenomenon behind this effect is examined by a study of static strain aging. The extent of strain-age yield point varies with aging time and temperature in a manner that confirms pipe diffusion of solute along dislocation cores as the process controlling dislocation pinning. The solute species responsible for pinning is identified as titanium present in excess of stoichiometry.