Abstract
According to the characteristics of the dislocations of which the small-angle grain boundaries consist, three kinds of small-angle grain boundary have been observed in annealed Al70Co15Ni15 decagonal phase for the first time by transmission electron microscopy: A tilt boundary consisting of an edge-dislocation wall; a twist boundary consisting of parallel screw-dislocation pairs; a small-angle grain boundary consisting of a dislocation network.