Positive-#TCE Tin manganese oxide is closely related to negative-TCE zirconium manganese oxide, and so by adjusting proportions of tin and zirconium, you can get a single-phase near-zero thermal expansion material, but the material is metastable and tends to separate. This is #popsci; the research is by John Evans at U Durham.
on 02015-08-16A #popsci article on #gelcasting #ceramics. Mentions that binder burnout takes “less than a day” as if that’s a short time!
on 02015-08-15ORNL developed #gelcasting for “technical” #ceramics #materials (including #silicon-nitride) in the 1980s and 1990s, and this is a #popsci overview; apparently Mark Janney, Stephen Nunn, Claudia Walls, and Ogbemi Omatete are recognized as the inventors. Apparently the advantage over slipcasting is that shrinkage is uniform and the green casting is strong enough to be machinable. Initial experiments used methylcellulose, which gels when heated with water, as the gelifying binder, but “multifunctional acrylate” polymers (??) were the binder that made gelcasting practical, followed by water-based #acrylamide, then less-toxic methacrylamide.
on 02015-08-15A #popsci explanation of negative-#stiffness #metamaterials or structures, with an #interview.
on 02015-08-12