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Item type:Publication, Access status: without files , LMDCAM, computer aided manufacturing (CAM) solution for tool path generation for build-up of complex aerospace components by laser metal deposition (LMD)(Old City Publishing, 2014-01-01); ; ; ; The success of laser metal deposition (LMD) for repair or fabrication of near-net shaped metals components directly from computer aided design (CAD) solid models without use of time and cost-prohibitive conventional techniques, such as five-axis milling, linear friction welding and electro chemical machining depends on the availability of a close CAD/ computer aided manufacturing (CAM) chain. Distortion and defects of a worn part implies that the nominal CAD model from the design stage is no longer suitable for the representation of the part geometry. This means that first of all the actual and the target geometry have to be constructed from which the deficit volume is determined. Only with this volume being available the tool paths can be programmed. The original data format of laser scanned data is a polygonal modelling approach for surface representation. The further step of creating a non-uniform rational B-spline (NURBS) representation of the geometry requires a major commitment in time, both in instruction and in amount of work. For this reason the Fraunhofer Institute for Laser Technology (ILT) designed a process chain for the laser material deposition (LMD) whose CAM module termed LMDCAM, is based on a polygonal modelling approach for geometry representation. NURBS are only used for the reduction of data noise in the scanned data. The target geometry of worn parts is derived by a best fit with the CAD model from the design stage. LMDCAM supports the generation of all sorts of path pattern within a layer which for example may be derived from a distortion reduction analysis. The functionalities of LMDCAM are exemplified by a repair application and the near-net fabrication of a blade-integrated disk (BLISK) blade direct from the CAD model.Publicationtype: Journal Article30 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Modeling of coaxial single and overlap-pass cladding with laser radiation(Springer, 2012-07); ; ; ; The repair with laser cladding of single crystalline Nibase superalloy gas turbine blades requires specific solidification conditions in order to realize an epitaxic dendritic growth front. For each superalloy there exists a process window concerning solidification conditions within the formation of new grains ahead of the epitaxic dendritic growth front can be prevented. In order to determine this process window a three-dimensional finite element model for laser cladding has been developed. This model emphasizes on a precise calculation of free surface shape of melt pool because the microstructure as processed depends essentially on the solidification conditions around the solidus/liquidus temperature. So due to the small distance between the melt pool surface and the growth front all errors concerning the approximation of melt pool surface and the implementation of boundary conditions will be mapped directly onto the solidification conditions. This model does not use any geometrical approximation of the melt pool surface but determines the melt pool surface shape by the balance equation for capillary forces.Publicationtype: Conference Paper29 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , LACAM3D, CAM solution for tool path generation for build up of complex aerospace components by laser powder deposition(Springer, 2012-07); ; ; ; This The success of Laser Metal Deposition (LMD) for repair or fabrication of near-net shaped metals components directly from CAD solid models without use of time and cost-prohibitive conventional techniques, such as five-axis milling, linear friction welding and electro chemical machining depends on the availability of a close CAD/CAM chain. Distortion and defects of a worn part implies that the nominal CAD model from the design stage is no longer suitable for the representation of the part geometry. This means that first of all the actual and the target geometry have to be constructed from which the deficit volume is determined. Only with this volume being available the tool path programmed. The original data format of laser scanned data is a polygonal modeling approach for surface representation. The further step of creating a NURBS representation of the geometry requires a major commitment in time, both in instruction and in amount of work. For this reason the ILT designed a process chain for the LMD whose CAM module, LACAM3D, is based on a polygonal modeling approach for geometry representation. NURBS are only used for the reduction of data noise in the scanned data. The target geometry of worn parts is derived by a best fit with the CAD model from the design stage. LACAM3D supports the generation of all sorts of path pattern within a layer which for example may be derived from a distortion reduction analysis. The functionalities of LACAM are exemplified by a repair application and the near-net fabrication of a BLISK (Blade-Integrated diSK) blade direct from the CAD model.Publicationtype: Conference Paper27