عنوان مقاله English
نویسندگان English
The influence of mechanical activation by ball milling (BM) of Ti, B and graphite powders mixture on the synthesis of B4C-TiB2 (1:1 mole ratio) composite by Spark Plasma Sintering (SPS) is investigated. The milled powders at 0, 3 and 8 h were chosen for investigation of synthesis mechanism, density and microstructure of powder and dense products. Results showed the milling influence on temperature and time of reactants conversion to products, but it does not have any effect on mechanism of synthesis. The synthesis process occurs through a solid-state diffusion mechanism where the first crystalline phase formed is TiB, which is gradually converted to TiB2, while the formation of B4C takes place subsequently. Investigation showed that with using 8 h milled reactant; nanostructure composite powder could be obtained. As a consequence of the mechanical treatment up to 8h, SPS product density increases from about 82% to 94% of the theoretical value. Correspondingly, a material with homogeneous phase distribution and grain submicron size is obtained.
کلیدواژهها English