Session *BB6.2

8:45 AM *BB6.2
LASER ENGINEERED NET SHAPING (LENSë): A CAD SOLID MODEL DRIVEN DIRECT FABRICATION SPRAY AND BEAM PROCESSING TECHNOLOGY. D. M. Keicher* , M. L. Griffith, J. E. Smugeresky, J. A. Romero, and L. D. Harwell, Sandia National Laboratories, Albuquerque, NM, and Livermore, CA; *Optomec Design Company, Albuquerque, NM.

The Laser Engineered Net Shaping (LENSô) process, currently under development for direct fabrication, is a metal spray forming-laser based technology that uses a high power Nd:YAG laser to fuse metal particles together as they are injected into the deposition region. With the LENSô process, designers use Computer-Aided Design (CAD) solid models, in electronic format, to drive the motion, deposition and power requirements for layered forming of functional metal parts. Using a highly localized laser beam, metal powders are used to produce near-net shape, fully dense metallic parts with reasonably complex geometrical features. The results of current studies suggest that, with continued improvement, this process will indeed be feasible for direct fabrication applications. The current approach lends itself to produce components with a dimensional accuracy of ± 0.002 inches in the deposition plane and ± 0.015 inches in the growth direction. These results suggest that the LENSô process will provide a viable means for direct fabrication of metallic hardware. With the continued development of faster, more powerful computers coupled with the existing level of the Rapid Prototyping techniques this technology is beginning to be exploited to fabricate reasonably complex geometrical features with fine grain microstructures and enhanced mechanical properties in metallic materials. Efforts are currently underway to improve surface finish and understand the interactions between the various process parameters so that process control methodologies may be developed for closed-loop process control. This paper gives a brief description of the LENSô process and the results that have been achieved to date.
Work supported by the U. S. Department of Energy under contract DE-AC04-94AL85000