The creep behavior of the near alpha -Ti alloy Ti6242Si is investigated at
500 degreesC using constant stress tensile creep testing. Emphasis is put o
n primary and anelastic creep and their dependencies on processed microstru
cture and applied stress. The results of steady state creep are also report
ed. It is shown that the primary creep strain depends strongly on microstru
cture. Its dependence on stress is linear in the low stress regime, whereas
a weak dependence is observed for high applied stresses. Unloading experim
ents lead to a time-dependent strain recovery that is also dependent on mic
rostructure and prior stress. Unloading in the primary creep regime results
in the recovery of almost all of the creep strain. However, a substantial
strain recovery was also obtained upon unloading from steady state. It is s
hown that primary and anelastic creep strains are intimately related, and d
epend on microstructure and stress. The results are discussed with respect
to existing dislocation creep models and the observed dislocation structure
s. (C) 2000 Elsevier Science Inc. All rights reserved.