The effect of activated slip systems upon a grain boundary pre-melting behavior in thin foils of 5N-purity material was elucidated. Specimens which had the same type of grain boundary, but differing tensile directions, were prepared by using a modified Bridgman method. They were then deformed in tension to a strain of 0.3. Transmission electron microscopic foils which contained the grain boundary were prepared, and were subjected to  in situ  heating in a 200kV transmission electron microscope. It was found that the melting of a grain boundary occurred at lower temperatures in bicrystals whose boundary planes were parallel to screw dislocations of the activated slip systems, than in bicrystals whose boundary planes were parallel to edge dislocations. The grain boundary pre-melting behavior in Ag bicrystals was similar to that in Cu ones.

T.Yoshikawa, F.Inoko: Journal of the Japan Institute of Metals, 1995, 59[5], 471-9