The Effect of Raw Material Ratios on the Fe-TiC/Al2O3 Composite Formation Mechanism

Ilmenite, aluminum and graphite can be used to produce in-situ Al2O3/TiC–Fe composites which are used as cutting tools. Few publications can be found in the literature that discusse the effect of molar ratio of aluminum and graphite on the Al2O3/TiC–Fe formation mechanism. Therefore, the present research is designed to make the issue clear.  To achieve this goal, at first, the mechanism of the Fe-TiC/Al2O3 composite formation from ilmenite, aluminum and graphite mixture with molar ratio of 1:2:1 was clarified. Then the samples with different molar ratios of aluminum and graphite were prepared. Both of aluminum and graphite ratios changed separately in this work. In the following, the samples were heat treated at 1300°C to be sure all reactions are completed. It was found that the optimum molar ratio of ilmenite, aluminum and graphite mixture is 1:2:1 because no undesired compound was detected in the products. Compared with the ratio of 1:2:1, increasing the aluminum content of the raw materials causes the TiAl3 formation while insufficient aluminum doesn’t allow the reactions to be completed. It also was found that using more graphite leads to form the Fe-C compounds and less graphite will cause the reaction not to be completed.