Tensile tests have been performedon a superplastic titanium alloy. Different strain rates from 5 10-4s-1 to 5 10-2 s-1 and various temperatures upto 1050°C were explored. The results of these tests, supplemented withmicrostructural investigations allow, as a function of temperature and strainrate, the determination of mechanical properties such as flow stress, strainhardening and fracture strain as well as the identification of mechanisms suchas grain boundary sliding, dynamic recrystallization and dynamic grain growth.A modified Norton-Hoff law is proposed to characterize the tensile behaviour ofthis alloy. All temperature-strain rate combinations have been grouped into anumber of domains, each corresponding to a particular deformation mechanism.For each domain the Norton-Hoff parameters have been determined. Closeagreement between the predicted and experimental stress-strain relationshipshas been achieved.status: publishe