GRAIN BOUNDARY MOTION IN VANADIUM

sample. The velocity of individual grain boundaries has been measured and compared to the average velocity determined from the normal grain growth taw. An analysis of the relation br162162 the veiocity ofcurved boundaries and their curvaturr is given. The results obtained prove that in the applied experimental circumstances the driving force of the grain boundary motion is the surface energy of the boundaries. Finally, a simple geometrical model is given for explaining the spasmodic migration of the boundarir joined to the surface, as well as the observed sudden breaking of cr grains.