Synthesis and robocasting of YAG xerogel: one-step conversion of ceramics

Abstract

An optimized sol–gel protocol was carried out to produce an yttrium aluminum garnet (YAG) xerogel from aluminum alkoxide and an yttrium salt on a semi-pilot scale. This xerogel was successfully used without prior pyrolysis as a solid load with the aid of additives in the preparation of pastes. Thermal treatment of the green bodies, obtained by robocasting of the paste, led to cohesive single-phase YAG ceramics. Manufacturing ceramic pieces by additive methods will allow shaping complex forms, while the single step conversion/consolidation would simplify the technological process, reducing global energy costs. Since YAG possesses high strength and good creep behavior at high temperatures, these refractory pieces could replace the metal alloys used in turbine blades for deep space exploration. Structural, thermal and chemical characterizations were performed on xerogel powders, pastes, and YAG ceramics.

Nondestructive characterization and artificial intelligence recognition of acoustic identifiers of ancient ceramics

“…When the boundary conditions of a structure are different, the natural frequencies must inevitably be different, because the boundary conditions will affect the distribution of elastic modulus of the structure. Meanwhile, the elastic modulus of ceramics is related to the phase type, particle size, distribution, proportion and porosity of ceramics [21,22].…”