Ts. Rong et al., COMBINATION TESTS ON TIAL INVOLVING CONSTANT STRAIN-RATE DEFORMATION,ANNEALING AND CREEP, Acta materialia, 46(13), 1998, pp. 4507-4517
Citations number
14
Categorie Soggetti
Material Science","Metallurgy & Metallurigical Engineering
Duplex tests involving constant strain-rate deformation and creep have
been performed on polycrystalline single-phase titanium aluminide of
nominal atomic composition Ti-52Al. It is found that prede-formation (
2%) at either room temperature or 800 degrees C speeds up the subseque
nt primary creep rate and increases the critical strain corresponding
to the minimum creep rate, but has little influence on the correspondi
ng rime, i.e. there is no obvious change in the time duration of prima
ry creep for the virgin and prestrained specimens. Double creep tests,
consisting of creep, annealing and creep, indicate that if the creep
test is interrupted for annealing in the primary creep region, the cre
ep rate decreases with time in the subsequent creep. However, if the c
reep is interrupted in the region of increasing creep strain rate, the
creep rate increases with time almost immediately after reloading. Mi
crostructures after various duplex deformations were examined by optic
al and electron microscopy. Generally, no evidence for recrystallizati
on was observed. These results are interpreted in terms of recovery: t
he acceleration in creep corresponds to an increasing misorientation a
cross the subgrain boundaries and therefore an increased mobility of t
hese. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Lt
d. All rights reserved.