材料期刊网

By making use of a novel technique in which TiB(2) particulates are fabricated by an in situ reaction in molten aluminum, we have successfully produced TiB(2)/Al composites. In order to reveal the characteristic of the technique, the mechanism of formation of TiB(2) particulates obtained by this method is studied in this article. Both theoretical and experimental results have shown that the TiB(2) particulates are formed by a diffusion mechanism when the molar fraction of aluminum in the preform is higher than 43.5 pet. In this case, the TiB(2) particulates are generally spherical, and their mean size is less than 2.0 mu m. On the contrary, the TiB(2) particulates are formed by a solution-precipitation mechanism when the fraction is lower than 43.5 pet. In this case, the TiB(2) particulates are multifaceted, and the size of most particulates lies between 3.0 and 6.0 mu m.