Annealing out of quenched-in vacancies in an ordered B2 type Fe-Al single crystal

On the path dependence of the thermal vacancy concentration in stoichiometric FeAl

“…This is consistent with prior studies of stoichiometric FeAl following similar heat treatments [6,14,15]. It is known that in iron-rich alloys, some dislocations with < 111 > Burgers vectors may also form during heat treatments designed to lower the vacancy concentration, but such defects were not observed here [16][17][18][19]. Fig.…”

The stress anomaly in FeAl–Fe3Al alloys

“…It is also noteworthy that experimental measurements of high vacancy contents in Fe-Al alloys have all selected alloys with about 40-50%Al for study, e.g. [36][37][38][39][40][41]59]. Extrapolating the trend seen in Fig.…”

“…More recently a vacancy hardening model has been suggested [14,35] based on the observations of large numbers of thermal vacancies at high temperatures in FeAl alloys [36][37][38][39][40][41][42][43][44][45][46][47][48] and the significant room temperature hardening produced by such vacancies [10,44,49,50]. This model considers that significant hardening is produced at temperatures below the anomalous stress peak, as the thermal vacancies are produced, since these are immobile, solution hardeners at such temperatures; at sufficiently high temperatures the vacancies become mobile, are able to move with whichever dislocations are present, and hence lose their hardening ability.…”

Demonstration of the g · b x u = 0 edge dislocation invisibility criterion for electron channelling contrast imaging

“…In order to demonstrate this, edge dislocations in FeAl have been imaged, utilizing a variety of TEM di racting and ECCI channelling conditions. The propensity of FeAl to take on high concentrations of thermal vacancies (Junqua et al 1973, Fourdeux and Lesbats 1982, Nagpal and Baker 1990) is well known. Upon cooling, these vacancies tend to form Frank-type edge dislocation structures (Junqua et al 1973, Morton and West 1974, Fourdeux and Lesbats 1982, with the Burgers vector normal to the plane of the dislocations.…”