Support-Free Infiltration of Selective Laser Sintered (SLS) Non-Metallic Preforms

点击翻译按钮获取中文摘要

The research objective of this project is to learn the origin of defects in infiltrated non-metallic parts produced using Selective Laser Sintering, a freeform fabrication technique. These part defects include incomplete filling by the infiltrant and localized infiltrant over-extrusion onto the surface of the part at surface irregularities. The approach is threefold. First, wetting theory will be extended to this problem and will establish a basis for defect origin. Second, guided by this scientific advance, a process will be created to remove and/or mitigate defects observed previously in silicon infiltrated silicon carbide parts. Last, the results of this scientific assessment will be verified by applying them to different part geometries that promote defect formation and to different materials systems including cobalt infiltrated tungsten carbide and epoxy infiltrated graphite.If successful, these research results will enable development and maturing of a new manufacturing route for creating low-cost non-metallic parts with complex geometry and excellent surface finish. Included are commercially important hard-to-process materials such as cobalt-tungsten carbide, silicon-silicon carbide and graphite-graphite. This will strengthen the domestic manufacturing infrastructure and enable domestic manufacturing to compete more effectively in the world market.