Tracer Diffusion in β‐Titanium

Tracer diffusion measurements in β‐titanium are reviewed and new data presented for solutes Sc 46 , Sn 113 , and P 32 . All Arrhenius plots are curved and give unusually low activation energies and frequency factors. Various explanations are outlined and it is suggested that monovacancy diffusion dominates but that divacancy contributions may become appreciable near the melting point. Impurity activation energies and diffusion rates are closely related to atomic size and compressibility.