Using nanoparticles filler rod feeding, fine coated layer can be formed successfully with higher deposition late. Nanometer sized alumina 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 ᶲ4×200 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 rate on stainless steel substrates. Effective dielectric constants of these coated layers were measured to estimate porosities by time domain spectroscopic method of electromagnetic waves in a terahertz frequency range. The reducing porosities in the coated layers through the optimization of filler rods feeding speeds and nanoparticles deposition rates will be discussed.

Solid resin rods including ceramics nanoparticles were fed successfully into a Rokide flame gun to create dense coated layers without micro cracks and pores applying for electric, magnetic and dielectric components. In this investigation, alumina particles of 170 nm in average diameter were dispersed into acrylic liquid resin at 40 % in volume fraction. The paste material was injected into an brass mold of φ4 ~ 200 mm in inner dimension and thermally cured through heating at 120 °C for 60 min. Formed solid rods were fed coaxially into an oxyacetylene gas flame by using the Rokide spraying system. Sprayed particles were collected in a water bath for microstructure observations by a scanning electron microscope and crystal phase analyses by an X-ray diffraction spectroscopy. Fine ceramics layer formations will be discussed systematically by the feeding speed of solid rods and gas flame condition of air pressure and oxygen pressure.