Net Shape Nanostructured Aluminum Oxide Structures Fabricated by Plasma Spray Forming

The spray forming of nanostructured Aluminum Oxide

“…3 In this study, the plasma-spray parameter IV/Ar ratio was 180. 12 The densification of spray-deposited nanostructured alumina occurred by solidification and sintering, which is in contradiction to the hypothesis of Shaw et al A higher degree of melting in the present research (IV/Ar ratio = 180) could be attributed to the difference in thermal conductivity values of Al 2 O 3 and TiO 2 . Al 2 O 3 has a thermal conductivity of 5.9 W/mK at 1,000°C, whereas TiO 2 has a thermal conductivity of 3.3 W/mK.…”

“…The evolution of bimodal grain-size distribution in the spray-formed Al 2 O 3 microstructure is due to the powder-flow behavior through the plasma and associated densification mechanism. 12 Micrometersize powder particles flow coherently …”

Observation of High Resolution Microstructures in Thermal Sprayed Coatings and Single Deposited Splats Using Ion Beam Milling

“…[17][18][19][20] Many researchers hence have made TEM samples by the FIB method from micron-sized powders or small splats or thick coating layers at a desired location. 1,[21][22][23][24][25][26][27][28][29] Because the FIB is an imaging tool in its own right as well as the milling and thinning capability in sample preparation, 30) during the FIB fabrication, one can check the milling state and get images of the sample.…”

“…1,[21][22][23][24] For the high resolution images, several researchers prepared firstly the cross section of a single splat by a conventional polishing method using silicon carbide (SiC) papers or the FIB method and then, from the cross section, several TEM samples were made respectively at desired locations within the single splat. [27][28][29] Once a TEM sample was made and observed, it is generally impossible to prepare much thinner sample at the desired position. By the FIB milling, however, it is possible to conduct re-thinning at any interested region even after TEM samples were already observed by electron microscopes.…”

FIB cross‐sectioning of a single rapidly solidified hypereutectic Al‐Si powder particle for HRTEM

“…We have characterized a hypereutectic Al-Si powder, which is subsequently used for plasma spray forming bulk parts (Agarwal et al, 2003;McKechnie, 2000), using advanced techniques such as FIB and HRTEM to determine the internal substructure of the powder.…”