Cold Hydrostatic Sintering: From shaping to 3D printing

Abstract We developed a novel consolidation technique, Cold Hydrostatic Sintering (CHS), which allows near full densification of silica. The technique is inspired by biosilicification and geological formation of siliceous rocks. Unlike established cold sintering method which is based on uniaxial pressure, CHS employs an isostatic pressure to enable room temperature consolidation of bulks having a complex three-dimensional shape. The resulting material is transparent (in line transmittance exceeding 70% in the visible range) and amorphous. After drying, the Vickers hardness was as high 1.4 GPa which half of materials consolidated at 1200 °C and it is the highest among all materials processed at room temperature. The CHS method, because of its simplicity, might be suitable for broad range of applications including 3D printing, mould forming and preparation of multi-layered devices. Because of the absence of the firing step, CHS could be directly integrated in the manufacturing of a wide range of hybrid (organic/inorganic) materials for functional and biological applications.