Session BB6.1

8:30 AM BB6.1
MICROSTRUCTURE AND PROPERTIES OF POWDERS CONSOLIDATED BY LASER ENGINEERED NET SHAPING (LENSô). J. E. Smugeresky, D. M Keicher*, M. L. Griffith, J. A. Romero, L. D. Harwell, Sandia National Laboratories, Livermore, CA, and Albuquerque, NM; *Optomec Design Company, Albuquerque, NM.

Laser Engineered Net Shaping (LENSô) is an advanced technology for consolidating metal powders into net shaped structural components directly from computer aided design files. This technology takes traditional polymer-based rapid prototyping processes one step further, where structural rather than surrogate or model materials are used. Considered to be a mold-less direct fabrication technology, the LENSô process produces shapes which provide rapid solidification microstructures, taking advantage of metastable conditions to enhance material properties. Critical to the success of this technology is the extent to which appropriate microstructure and mechanical properties can be achieved while simultaneously forming to net shape. Considerable promise has been demonstrated with extremely fine grain sizes resulting in yield strengths more than twice that of conventionally processed annealed stainless steels, with little or no reduction in ductility. Improvements in properties have also been obtained in Incoloy 625, although not as dramatic as in stainless steel. Tool steel materials, such as H13, have shown hardness values of 61 Rc, where the microstructure can be tailored by certain additions. This paper will discuss the relation between the microstructure and properties of these materials as they are affected by processing conditions.
Work supported by the U. S. Department of Energy under contract DE-AC04-94AL85000