Hot-working characteristics of Zircaloy-2 in the temperature range of 650–950°C

Characterization of hot deformation behavior of Zr–1Nb–1Sn alloy

“…At _ e P 1 s À1 and at all temperatures of testing, oscillatory flow curves indicating inhomogeneous flow behavior were obtained. Similar oscillatory flow curves have also been reported in various Zr alloys at _ e > 1 s À1 [5][6][7][8][9][10]. Table 1 gives the r, _ e, T data at e = 0.5.…”

“…In these investigations it was found that the dynamic recrystallization (DRX) of a phase is the dominant high temperature process during deformation in both a and a + b phase fields. As regards the effect of alloying addition on the deformation characteristics, it has been observed that a stabilizers have virtually no effect on hot deformation behavior of the a phase while addition of b stabilizers like Nb alter the deformation characteristics dramatically [5,8,9]. For example, addition of 2.5 wt% Nb lowers the strain rate required for DRX by two orders of magnitude compared to that required for DRX of unalloyed Zr.…”

“…Several processes such as recovery, recrystallization and superplasticity, which occur dynamically during the hot deformation of zirconium alloys containing both a and b stabilizers have been identified earlier [5][6][7][8][9][10]. In these investigations it was found that the dynamic recrystallization (DRX) of a phase is the dominant high temperature process during deformation in both a and a + b phase fields.…”

Dynamic Recrystallization in Sintered Cobalt during High-Temperature Deformation

“…The temperature and strain rate corresponding to peak m is usually taken as the optimum processing conditions. [18,19] In comparison, the processing map of wrought cobalt has shown a single domain with a peak m occurring at 5 9 10 À2 s À1 and 1123 K (850°C). [1,2] While the peak m value and the corresponding strain rate are higher for the wrought cobalt, the temperature corresponding to peak is lower than that of sintered cobalt.…”

“…Further, since m > 0 over the entire strain rate and temperature range employed in this study, the sintered product is not expected to exhibit flow instability in the strain rate-temperature regime of this investigation. However, detailed work is in progress, using various instability criteria [19,20] to identify the strain rate temperature combination resulting in inhomogeneous deformation.…”