Friction-rolling　additive　manufacturing　(FRAM)　is　a　solid-phase　additive　manufacturing　technique　that　relies　on　tool-driven　material　deposition　and　interlayer　bonding.　However,　the　interfacial　bonding　and　formation　mechanisms　induced　by　toolhead　features　are　unclear.　In　this　study,　a　three-dimensional　thermomechanical　coupled　Eulerian-Lagrangian　(CEL)　model　was　developed　by　incorporating　a　damage　constitutive　model　that　reflected　the　friction　between　various　toolhead　features　and　the　damaged　material.　This　study　systematically　investigated　the　heat　generation　and　material　flow　behavior　around　the　toolhead　with　different　features　and　evaluated　their　effects　on　the　interfacial　bonding　and　microstructure.　The　results　showed　that　the　groove　feature　enhanced　material　disruption　in　the　forward　region　of　the　toolhead,　thereby　reducing　the　heat　generated　by　friction　and　accelerating　the　overall　accumulation　of　plastic　deformation.　This　significantly　increased　the　material　capture　ability　and　plasticized　zone　range.　The　material　flow　is　influenced　by　the　combined　effects　of　shearing　and　extrusion　around　the　toolhead,　which　subsequently　affects　the　interface　morphology.　The　groove　features　promote　upward　migration　on　the　substrate　surface,　forming　a　mechanical　interlocking　structure　at　the　interface.　In　addition,　the　groove　features　significantly　enhanced　recrystallization　in　the　deposition　layer,　achieving　a　grain　refinement　of　up　to　80%　of　the　base　material　size.　These　findings　reveal　the　interaction　mechanisms　between　toolheads　and　materials,　which　offer　further　insights　into　toolhead　design　and　optimization.