Synthesis of nanostructured spherical aluminum oxide powders by plasma engineering
Abbreviated Journal Title
Metall. Mater. Trans. A-Phys. Metall. Mater. Sci.
RAPID SOLIDIFICATION; COATINGS; MICROSTRUCTURE; KINETICS; ALLOYS; Materials Science, Multidisciplinary; Metallurgy & Metallurgical; Engineering
Irregularly shaped aluminum oxide particles were plasma atomized resulting in narrow size range distribution of spherical nanostructured powders. Cooling rates, on the order of 10(6) to 10(8) K/s, were obtained from the different quenching medias, viz. air, water, and liquid nitrogen. Plasma-engineered powder particles developed nanosize crystallites, while solidification provided insight into the morphological feasibility in refinement of grain size. X-ray diffraction (XRD) methods have been used to quantify the crystallite size obtained with different quenching media. Raman peak shift validated the X-ray analysis in anticipating the grain refinement with increasing cooling rates. Salient structural morphology characteristics and a detailed understanding of spheroidized plasma-sprayed alumina powders were analyzed through scanning electron microscopy (SEM) studies. Formation of nanograins, novel metastable phases, and amorphous structure were endorsed by transmission electron microscopy (TEM) investigations.
Metallurgical and Materials Transactions a-Physical Metallurgy and Materials Science
"Synthesis of nanostructured spherical aluminum oxide powders by plasma engineering" (2005). Faculty Bibliography 2000s. 5377.