Synthesis and Characterization of Plasma Synthesized Nanostructured Magnesia-Yttria Based Nanocomposites

摘要

Polycrystalline Y_2O_3 is the material of choice for IR applications since it has excellent optical properties in the visible, and near infra-red band. However, current processing methods yield polycrystalline Y_2O_3 with large grain size (> 100μm), which limits the hardness and erosion resistance attainable. One way to improve strength is to develop an ultra-fine grained material with acceptable optical transmission properties. To realize a fine-grained ceramic, one approach is to develop a duplex-phase or composite structure, in which one phase inhibits the growth of the other phase during processing. In this study, Y_2O_3-MgO nanocomposite with various MgO content (20, 50 and 80 mol%) were synthesized using new plasma spray and flame synthesis techniques. Moreover, the mechanical and optical properties of a uniformly consolidated finegrained ceramic composite, comprising a 50:50 vol% mixture of Y_2O_3 and MgO, are measured and correlated with structure. Transmission Electron Microscopy imaging, as well as EDS chemical mapping, revealed that the consolidated sample have bi-continuous MgO-Y_2O_3 nanostructure with an average grain size of 200 nm.