Binder Technology for Large Metal Parts Produced using Three-Dimensional Printing

摘要

Three-Dimensional Printing (3DP) provides a rapid solid freeform fabrication process which can create functional metal components directly from a CAD model. As-printed 3DP parts, however, have relatively low green density (typically 60%) since there is no mechanical interlocking between metal particles. The adhesive strength of the binder is the sole source of metal particle bonding. To ensure shape retention, the binder must provide a sufficient green strength for part handling and then hold the metal particles together during heating until sintered bonds form. This requirement is even greater for large parts. New binders that provide high strength in both the green state and during heating or sintering will be presented. These binders also have the advantage that some residual elements become a beneficial part of the final sintered alloy. Examples will be given of the capabilities of the process to produce large, functional prototypes as well as intricate parts and molds with complex internal channels.