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Europium doped CaAl2O4 nanocones have been grown first time by thermal evaporation method. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to analyze the morphology, size and crystal structure of the nanocones. The body of the nanocones are about 2–20 μm in length and their diameters are 200 nm to 1 μm at one end and tapers off to a ~ 40–200 nm at the tip end. The as-synthesized nanocones are single crystalline in monoclinic structure and grow along the [010] direction and the normal direction of (100) and (001). The room temperature photoluminescence (PL) and cathodoluminescence (CL) spectrum measurement reveals that CaAl2O4:Eu2+ nanocones emit light at about 440 nm. [ABSTRACT FROM AUTHOR]

In this study we utilized two types of plasma spray processing, namely atmospheric plasma spraying (APS) and hypersonic plasma spraying (HPS) to produce structural bulk titanium aluminides. Microstructure characterisation of the deposits, their compositional changes and phase transformations were investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. It was found that the TiAl alloyed powder particles experienced a significant phase change during both APS and HPS processes. During APS the TiAl alloyed powder particles also experienced a significant compositional change; having a considerable amount of titanium oxides. On the other hand, the compositional change during HPS was negligible. At the end of the paper, an attempt of using a low temperature spraying process, i.e. cold gas dynamic spray, was reported as an alternative coating method. [ABSTRACT FROM AUTHOR]