In-Flight Temperature And Velocity of Powder Particles of Plasma Sprayed TiO2

Abstract

This paper relates to the in-flight temperature and velocity of TiO2 particles, an integral part of the systematic research on atmospheric plasma spraying of the material. Initial powder feedstock (32-45 um, 100% rutile phase) was introduced into the plasma jet. Six parameters were selected to represent the versatility of the plasma system and their respective influences were determined according to basic One-at-a-time and advanced Taguchi design of experiments combined with analysis of variance analytical tool. It was found that the measured temperatures varied from 2121 K to 2830 K (33% variation), while the velocities of the particles altered from 127 m/s to 243 m/s (91% variation). Gun net power was detected as the most influential factor with respect to the velocity of the TiO2 particles (an increase of 8.4 m/s per 1 kW increase in net power). Spray distance was determined to have a major impact on the in-flight temperature (a decrease of 10 mm in spray distance corresponds to a drop of 36 K). A significant decrease in both characteristics was detected for an increasing amount of powder entering the plasma jet: a drop of 7.1 K and 1.4 m/s was recorded per every +1 g/min of TiO2 powder.

This paper relates to the in-flight temperature and velocity of TiO2 particles, an integral part of the systematic research on atmospheric plasma spraying of the material. Initial powder feedstock (32-45 um, 100% rutile phase) was introduced into the plasma jet. Six parameters were selected to represent the versatility of the plasma system and their respective influences were determined according to basic One-at-a-time and advanced Taguchi design of experiments combined with analysis of variance analytical tool. It was found that the measured temperatures varied from 2121 K to 2830 K (33% variation), while the velocities of the particles altered from 127 m/s to 243 m/s (91% variation). Gun net power was detected as the most influential factor with respect to the velocity of the TiO2 particles (an increase of 8.4 m/s per 1 kW increase in net power). Spray distance was determined to have a major impact on the in-flight temperature (a decrease of 10 mm in spray distance corresponds to a drop of 36 K). A significant decrease in both characteristics was detected for an increasing amount of powder entering the plasma jet: a drop of 7.1 K and 1.4 m/s was recorded per every +1 g/min of TiO2 powder.