Atomic structure of grain boundaries

A field-ion microscopic study was made of the atomic structure of grain boundaries in a tungsten--thorium alloy (1% Th) and in molybdenum of technical purity grade. A study was made of the geometric structure of the boundaries with misorientation angles of 38 and 34/sup 0/. It was found that the boundary structure was complex. Dislocations with b=a/2 (111) in the (101) plane were found in the alloy and the projection of these dislocations along the (115) direction was a/6 (115).