The Preparation Of Nanometer Ultrafine TiO₂ Powder And Microwave Synthesis Of Titanium Nitride,Titanium Carbide And Titanium Carbonitride Powder

The thesis is composed of two parts:<1>the preparation of the ultrafine titanium dioxide powder with nanometer sizes by homogeneous precipitation mathod;<2>the synthesis of titanium nitride titanium carbide and titanium carbonitride powders by microwave heating method.Part one: Titaniferous solution-the resourceful and cheep medium products of the industrial production of titanium dioxide powder had been employed, high pure and ultrafine TiO₂ powder with about 30 nanometer in diameter on the average was prepared by homogeneous precipitation method. The equipment involved in experiment was very simple,the precipitating rate was high, it was easy to be controlled in processing and industrially produced. The effects of the synthetical processes and conttitions on the hydrolyzing precipitation of titaniferous solution had also been investigated. The results showed that in the particles of precipited titanic acid through hydrolyxing titaniferous solution, above 80% were the primary fine particles, the rest were the secondary and tertiary particles, thus the width of particle distribution was formed, which was decided by the properties of titaniferous solution itself. When the reaction temperature was reduced from the boiling point to 86℃, there was some decrease of the precipitated particle sizes and ditributions, but the reaction time had been greatly prolonged from about 1 hr to about 14 hrs. There were no influences on the size of the primary particles when the non-ionic surfactant was put in. Its space restriction effect had certain effects on the growth of the secondary and tertiary particles, more over, better effects were achieved by the surfactant with low molecular weight. The thesis provided the formulae of the precipitating rate the primary , secondary and tertiary particle sizes of the hydrolyzing reaction as the reaction time is changed. Finally the suitable preparing conditions for ultrafine TiO₂ powder with nanometer size were that half as much again as the stoichiomatrical urea of the reaction and three percent of non-ionic surfactant with low molecular weight were added in concentrated titaniferous solution reaction temperature was 106℃ reaction time was 60-80 mins and the nanometer titania powder could be obtained through washing, drying and firing at 500℃ for 1 hr.Part two: the nanometer titania fine powders from part one , the commencial anatase type of TiO₂ and rutile type of TiO₂ were respectively mixed with the carbon blacks which were C₁ C₂ and C₃, the method of carbothermal reduction was used to synthesize...