Fig. 2.

FeAl, as deformed by HPT and heated up to temperatures above the peaks I, II and III (cf. Fig. 1). (a, b) The as-deformed state. (a) TEM dark-field image (g = [200]). The grain that is in contrast is encircled with a dotted white line. (b) Diffraction pattern. The positions of the rings of the B2 superstructure are marked by arrows; at this position, no contrast is encountered in (b). (c, d) Dark-field image (g = [200]) and diffraction pattern after heating up to 220 °C. The rings of all B2 reflections are indexed. (e, f) Dark-field image (g = [200]) and diffraction pattern after heating up to 370 °C. The reduction in the grain size is visible. (g, h) Bright-field image and diffraction pattern after heating up to 500 °C. The grain growth leads to large grains free of dislocations.