Ceramics Filler Rods Feeding for Gas Flame Torch in Thermal Nanoparticles Spraying

Using thermal nanoparticles spraying, fine coated layer can be formed successfully with higher deposition late. Nanometer sized alumina or zirconia particles of 200 nm in average diameter were dispersed into liquid resins at 40 % in volume fraction. The obtained pastes were solidified through heat polymerization to crate composite rods of Φ4×200 mm in dimensions. The solid rods were introduced into an acetylene and oxygen gas flame torch for a coaxial direction at 5.0 mm/s in supplying speed by using a mechanical actuator. Fine coated layer of 500 μm in thickness could be formed at 100 μm/s in deposition late on steels substrates. Effective dielectric constants of these coated layers were measured to estimate porosities by time domain spectroscopy of electromagnetic waves in a terahertz frequency range. The porosity decreasing by optimization of the filler rods feeding speeds will be discussed.