Spherical Titanium Dioxide Powder's Preparation And Plasma Spraying Experiments

The titanium resources are very rich in our country, and the reserves are forefront in the world. Titanium dioxide has been a considerable scale of production; The coating of titanium dioxide made by Surface of matrices material which was processed from spraying of plasma can improve the quality of wear-resisting and resisting losing, anti-oxidant and hot impact largely. Therefore, the coating of titanium dioxide has a broad application prospect. The body of titanium white powder can't be used for spraying directly, its main reasons are these two:first, the diameter of particle is too small, its quality is too light, the body of powder is apt to reunite and flow ability is not good. Thus, lead to give powder hard; second, the activity of fritting of powder body is so high that it is difficult to receive the coating of the nanometer structure after spraying. So, to make dioxide nanometer titanium white powder which can apply to hot spraying directly is the key.In this subject, I applied the method of centrifugal spray granulation, and the raw materials used for the titanium powder which were obtained through the deep-processed titanium dioxide, with polyvinyl alcohol (PVA) as surfactant, glycerin (C3H8O3) for the lubricant, a certain amount of water (H2O) as diluents, first dry the slurry into particles by spraying. Then placed the dry particles into the sintering furnace which was filled with hydrogen, heating them under high-temperature until they were totally restored; Finally, we got the new black spherical titanium dioxide powder. This black powder was of non-toxic, non-magnetic, high relative density and had a good quality of heat-resistant, it was accord with the demands for spraying of plasma basically.Experimental results showed that by using of spray drying granulation method, the titanium dioxide powder became basically spherical and diameters were about 65um, I studied four different temperature levels:1100℃,1200℃,1300℃,1400℃,When the sintering temperature was 1100℃, the color of the products was gray and had a loose structure, so they could not meet the requirements of experiment. When the temperature came to 1200℃, it looked like black mixing a little blue-green and its structure was less loose than before. Until the temperature was 1300℃,its color totally became black which met the requirements. However, the structure was too dense too crush and pulverize when the temperature came to 1400℃.To conclude, controlling the temperature 1300℃was the best.In this subject, I discussed the influence on oxidizing the titanium particle performance of raw materials powder, frit temperature, frit time and other factors. Besides, I used granularity appearance, micro-sclerometer, electron omnipotent testing machine, SEM electric mirror, infrared spectrocomparator and other furniture to signify titanium dioxide particle and coating. The results showed that this powder had a better mobility, electrical conductivity, landed powder ratio, coating density and intensity. Therefore, it could be basically applied to industrial production.