X-RAY TOPOGRAPHIC OBSERVATION ON THE ANNEALING PROCESS OF PURE IRON CRYSTAL

The annealing process of a thin crystal of zone-refined pure iron has been investigated using X-ray transmission topography. Dislocation structures of (100) crystal were successively observed after annealing at 630, 780 and 840-degrees-C. The dislocation density was about 5 x 10(3) cm-2 after annealing at 780-degrees-C, and 5 x 10(2) cm-2 after annealing at 840-degrees-C. The Burgers vector of the dislocation resolved individually was a/2[111]. The dislocation line became straight and short, and lay on the {110} plane after annealing.