Robocast Pb(Zr_0.95Ti_0.05)O₃ Ceramic Monoliths and Composites

Abstract

Robocasting, which is a computer-controlled slurry-deposition technique, was used to fabricate ceramic monoliths and composites of chemically prepared Pb(Zr 0.95 Ti 0.05 )O 3 ceramics. The densities and electrical properties of the robocast samples were equivalent to those obtained for cold isostatically pressed parts formed under a pressure of 200 MPa. Three-layer robocast composites that consisted of alternating layers of different sintered densities-93.9%/96.1%/93.9%-were fabricated using different levels of organic pore-former additions. Modification from a single-material to a multiple-material deposition robocaster was essential for the fabrication of composites that could withstand repeated cycles of saturated polarization switching under fields of 30 kV/cm. Furthermore, these composites withstood a poled ferroelectric-to-antiferroelectric phase transformation that was induced by a hydrostatic pressure of 500 MPa, during which strain differences on the order of 0.8% occurred between the composite elements.

Additive Manufacturing of Ceramic‐Based Materials

“…Received: January 16,2014 Final Version: February 27, 2014 C [284] ZrC [160] TiC/Ni [289] Al 2 O 3 -ZrO 2 [191] Polymer-derived ceramics: see present work Functional ceramics BaTiO 3 [40,41] PZT [89] PZT [211,223,239] BaTiO 3 [150] SiO 2 -Al 2 O 3 -RO-glass [269] PZT [37,[45][46][47] BaTiO 3 [115] SiCN [225] PZT [145,146] LZSA-Glass [272] TiO 2 [43,44] PMN [192] PZT [282] LSMO/YBCO [48] LiFePO 4 [170] Li 4 Ti 5 O 12 BaZrO 3 , SrTiO 3 , BaMn 2 Al 10 O 19À x [193] ITO [119] ZnO [119,187] La(Mg 0.5 , Ti 0.5 )O 3 [167,188] Zr 0.8 Sn 0.2 TiO 4 [188] TiO 2 [119] Bioceramics HA [50,66,67,[69][70][71][72] Apatite-Mullite [107][108]…”

“…[133,144] Further development led to utilizing colloidal gels with different rheological properties, which could retain the shape without drying. [145] These [169] [119,123,124,130,137,138,[140][141][142] Technique…”

“…Deposition devices proved to deposit more than one material in one workpiece either by mixing pastes or by alternating deposition and thus achieved graded structures. [145,156,159,160] …”

“…They include filters, laboratory equipment, catalysts, and catalyst carriers (Robocasting Enterprises LLC). Extrusion freeformed parts may find usage as solid ceramic prototypes, [137] photonic bandgap structures, [119,[167][168][169] piezoactuators, [145] microbatteries, [170] graded structures, [160] biomaterials, [125,144,147,154,155,164,[171][172][173][174][175][176][177][178][179][180][181][182] as well as military and aerospace applications, such as radomes and missile propulsion nozzles. [160] …”

Dense and near-net-shape fabrication of Si3N4 ceramics

“…Ceramic components with simple or complex shapes can be rapidly produced form a computer aided-design drawing directly to a finished component that requires little or no machining after fabrication. The highlighted of this novel technique is moldless and binderless, and ceramics parts can be formed, dried, and sintered within 24 h. This procedure uses the deposition of highly concentrated colloidal slurries with low organic content (<1 wt%) to construct complex, three-dimensional (3-D) components in layer-by-layer built sequence [121,122]. Robocasting has great promise for the rapid manufacture of complex, multiphase assemblage devices, such as piezoelectric ceramic-polymer composites, photonic-band-gap lattices as well as Si 3 N 4 ceramics in advanced engines and gas turbines.…”