Mechanical Alloying Preparation Of Tib <sub> 2 </ Sub> Powder

Two new fabrication technology, Self-propagating High-temperature Syntheses (SHS) and Mechanical Alloying (MA), were widely applied in the field of material science. Reactive Ball Milling technology appeared after self-propagating phenomenon in the process of ball milling was discovered.Compound powders of TiB2 and MgO were prepared by ball milling with TiO2, B2O3 and MgO as raw powders. The changes of temperature and heat effect of reaction during ball milling were studied, and reactive thermodynamics was analyzed. Components, granularity and microstructure of the resultants were examined, and the crystal lattice constants of the resultants was computed and analyzed. Raw powders of TiO2, B2O3 and MgO were analyzed with DTA. The dynamics influencing factors during ball milling were studied. Mechanism of Reactive Ball Milling was discussed.The resultants of ball milling, TiB2 and MgO, were purified and cleaned with hydrochloric acid. Components and microstructure of purified specimens were examined. The influence of hydrochloric acid density, volume of hydrochloric acid, temperature and time of purifying were studied. Reactive thermodynamics during purifying and cleaning was analyzed.From all of the work and experiments, the following conclusion could be drawn: At normal temperature, compound powders of TiB2 and MgO, which can be separated and purified by hydrochloric acid, can be prepared successfully by ball-milling with TiO2, B2O3 and MgO as raw powders. During the course of ball milling, there was a rise of temperature, which accord with the value of theory well and proved that there was a exothermic reaction which happened suddenly and completed soon. This ball milling reaction was a sudden and fast self-propagating reaction, not a gradually diffusing reaction.