Special non-CSL grain boundaries in tungsten: Misorientation distribution and energetics

• Misorientation distribution is reported for cold-drawn W.
• Substantial anisotropy is demonstrated for misorientation angle distribution.
• Low-cohesive-energy GBs with special non-CSL misorientations were revealed.

As observed by field ion microscopy, a substantial part of randomly selected high-angle GBs in hard drawn tungsten wire, are those terminated by a low index plane and the medium index complements to this surface, which occur at special non-CSL misorientations. These GBs are special with respect to their misorientation distribution and are correlated to the intergrain cohesive energy. The GBs have revealed a high resistance to mechanical stresses approaching a significant fraction of the theoretical strength.