Bottomâ up vs reactive sintering of Al2O3â YAGâ YSZ composites via one or threeâ phase nanoparticles (NPs). Bottomâ up processing wins this time

The bottomâ up approach describes the synthesis of bulk materials from the finest possible length scales to obtain the best global properties. This approach was adapted to the synthesis of multiâ phase ceramic composites produced from metal oxides produced by liquidâ feed flame spray pyrolysis (LFâ FSP). The effect of length scale of mixing was tested through two processing schemes, mixed single metalâ oxide nanopowders (NPs) and nanocomposite NPs having the desired composition within single particles. For the Al2O3â Y2O3â ZrO2 ternary system, composites prepared from nanostructured nanoparticles sinter to finer grain sizes (<410Â nm) at equivalent densities of 95%TD than those prepared from mixed nanoparticle processing. These contrast with our previous studies in this area where mixed NP processing gave the best or equivalent results. The nanocomposite NPs produced in this study exhibit novel nanostructures with three phases contained within single particles