Stronger Ceramics Via 3-D Printing

Additive manufacturing methods are widely used to make intricately shaped products from polymers and metals. Three-dimensional printed ceramics, however, which could benefit aeronautics and thermal protection systems, are much less common because of challenges imposed by many ceramics’ very high melting points. The limited range of products made this way is formed by using a gluelike material to bind ceramic powders or by fusing them with a laser. But those methods are slow and typically yield porous products that are weak and prone to cracking. Zak C. Eckel, Tobias A. Schaedler, and coworkers at the R&D firm HRL Laboratories may have a solution. The team has shown that various monomers can be cured with ultraviolet light in a 3-D printer to form intricately shaped polymer structures that can be pyrolyzed to yield strong, nonporous ceramic products (Science 2016, DOI: 10.1126/science.aad2688). For example, from siloxane-based resins, the team formed silicon oxycarbide products that exhibit higher strength than ceramic foams of similar density.