TheweldingbehavioroftheFe–Co–7 wt%Vultra-thinfoilswasexaminedusingtheNd:YAGlaserwelding method.Scanningelectronmicroscopyandelectronbackscattereddiffractionwereusedtoinvestigate microstructuralchangesandfracturemechanismoftheweldjoints.Tensiletestandmicrohardness measurementwereemployedinordertostudythemechanicalbehaviorsofthewelds.Microstructural observationsindicatedthatabimodalgrainsizedistributionisseeninthefusionzone.Itwasfoundthat thefracturesurfacesoftheweldsconsistofbothcleavagesitesanddimples.Itwasalsorevealedthatthe cleavagesitesaremainlylocatedinthecoarsegrainzonewhilenumerousdimplesarelocatedinthe fine grainzone.Consideringthephasetransformationswhichoccurinthebasemetal,variationofthe microhardnessindifferentregionsoftheweldswasdiscussed.Theresultsdemonstratedthatthefusion zoneandheataffectedzoneofweldedsamplesexperienceasignificantdecreaseintheirhardness.