TiAlN　coatings　with　self-assembled　nanolamellar　structures,　synthesized　via　low-pressure　chemical　vapor　deposition　(LPCVD),　represent　a　leading　material　system　for　high-performance　cutting　tools.　While　their　layered　architecture　has　been　explored　extensively,　the　nature　and　evolution　of　associated　crystal　defects—particularly　dislocations—remain　insufficiently　understood.　In　this　work,　dislocation　morphologies　within　〈111〉-textured　columnar　TiAlN　grains　were　systematically　investigated　using　multi-scale　electron　microscopy　on　cross-sectional　and　plane-view　TEM　specimens　prepared　by　focused　ion　beam　(FIB)　milling.　High-density　(∼1015　m−2)　dislocation　arrays,　nearly　perpendicular　to　the　lamellae,　were　consistently　observed　and　exhibited　symmetric　feather-like　contrast　in　the　cross-sectional　samples.　These　long　(∼200　nm),　straight　dislocations　were　identified　as　mixed　full　dislocations　with　Burgers　vectors　of　b　=　½　〈110〉.　Originating　from　three-fold　pyramidal　ridges,　these　dislocations　propagate　through　grains　along　directions　closely　aligned　with　their　Burgers　vectors,　indicating　a　dominant　screw　component.　This　was　further　validated　by　spiral　features　revealed　through　atomic　resolution　HAADF　imaging.　These　findings　support　a　dislocation-assisted　growth　mechanism,　in　which　the　screw　components　act　as　persistent　atomic　step　sources　that　facilitate　vertical　grain　growth　along　three　〈001〉　directions,　thereby　reinforcing　the　observed　〈111〉　texture.　This　dislocation-mediated　growth　mechanism　provides　new　insights　into　the　defect-microstructure　interplay　in　LPCVD　TiAlN　coatings　and　offers　guidance　for　the　microstructural　design　of　high-performance　CVD　coatings.　©　2025　Elsevier　B.V.