The peculiarities of solid state joint (SSJ) formation under conditions of
superplastic forming (SPF) were investigated for the titanium alloy VT6S (T
i-6Al-3V). The influence of annealing and SPF on the change of state of the
alloy surface was considered. A significant role of grain boundary sliding
(GBS) in the formation of both surface microrelief and SSJ was established
. It was shown that SSJ formation under SPF conditions is primarily a defor
mation process. Corresponding schemes of the appearance of surface microrel
ief and SSJ formation are proposed.