### Continuous and Discontinuous αTi Layers Between Grains of β(Ti,Co) PhaseContinuous and Discontinuous αTi Layers Between Grains of β(Ti,Co) Phase

Access Restriction
Subscribed

 Author Straumal, B. B. ♦ Gornakova, A. S. ♦ Prokofjev, S. I. ♦ Afonikova, N. S. ♦ Baretzky, B. ♦ Nekrasov, A. N. ♦ Kolesnikova, K. I. Source SpringerLink Content type Text Publisher Springer US File Format PDF Copyright Year ©2013 Language English
 Subject Domain (in DDC) Technology ♦ Engineering & allied operations Subject Keyword cobalt ♦ grain boundaries ♦ solid phase ♦ titanium ♦ wetting ♦ Characterization and Evaluation of Materials ♦ Tribology, Corrosion and Coatings ♦ Quality Control, Reliability, Safety and Risk ♦ Engineering Design Abstract The microstructure of Ti-Co polycrystals with 1.6 and 3.2 at.% Co has been studied between 690 and 810 °C after long anneals (720-860 h) in the αTi+β(Ti,Co) two-phase area of the Ti-Co phase diagram. It has been observed that depending on the annealing temperature and GB energy, the αTi phase forms either chains of separated lens-like precipitates or continuous uniform layers along β(Ti,Co)/β(Ti,Co) GBs. In other words, β(Ti,Co)/β(Ti,Co)GBs completely or partially wetted by the αTi phase were observed. At 690 °C, slightly above eutectoid temperature T $_{et}$ = 685 °C, the portion of the completely wetted β(Ti,Co)/β(Ti,Co) GBs is 25% for the Ti-1.6 at.% Co alloy and 60% for the Ti-3.2 at.% Co alloy. It increases with increasing temperature and reaches the maximum of 80% for the Ti-1.6 at.% Co alloy at 780 °C and of 75% for the Ti-3.2 at.% Co alloy at 750 °C. At 810 °C, i.e., close to the upper border of the αTi + β(Ti,Co) two-phase area of the Ti-Co phase diagram, the portion of the completely wetted β(Ti,Co)/β(Ti,Co) GBs drops down to 40% for the Ti-1.6 at.% Co alloy and 20% for the Ti-3.2 at.% Co alloy. Thus, it has been observed for the first time, that the portion of grain boundaries completely wetted by the layers of a second solid phase can non-monotonously depend on the temperature. ISSN 10599495 Age Range 18 to 22 years ♦ above 22 year Educational Use Research Education Level UG and PG Learning Resource Type Article Publisher Date 2013-11-26 Publisher Place Boston e-ISSN 15441024 Journal Journal of Materials Engineering and Performance Volume Number 23 Issue Number 5 Page Count 5 Starting Page 1580 Ending Page 1584