Development of transfer functions for controlling fabrication of components by laser net shape deposition (LNSM)

Although laser cladding was developed thirty years ago, it has only been in the last ten years that research groups and companies have begun to exploit this technology to produce fully dense, near-net shape components with metals through techniques such as Direct Metal Deposition (DMD), Directed Light Fabrication (DLF), Laser Consolidation (LC), or Laser Engineered Net Shape (LENS). In order to produce components with fine features, it is necessary to provide proper thermal management of the weld pool during deposition. This is achieved by two means. First, proper choice of process parameters must be made to generate uniform deposits. Second, external sensor and control strategies must be employed to insure that the weld pool size is stable during the course of deposition. In this paper, the process for developing the transfer functions for laser net shape manufacturing (LNSM) is discussed. Finally, the strategy for how these transfer functions can be combined with sensors to control deposition is outlined.