Effect of CaCl2 on Microstructure of Calciothermic Reduction Products of Ti2O3 to Prepare Porous Titanium

The compound CaCl2plays a significant role in the process of direct calciothermic reduction of Ti2O3to prepare porous titanium. In this paper, the effect of CaCl2on reduction products by calciothermic reduction of Ti2O3was investigated. Results show that the distribution of CaCl2in reduction preform influences particle size and morphology differences in reduction products both on the surface and the inside. The CaCl2is transferred to the surface of the Ti2O3preform due to its volatilization before and throughout reduction. The content of CaCl2in the surface zone of Ti2O3preform is significantly higher than that in the interior during the reduction process, contributing to the formation of large Ti particles with a smooth shape on the surface, and small Ti particles with inherited morphology of Ti2O3inside. More CaCl2causes the aggregation of Ti particles to form large Ti particles which are advantageous as they connect and form a more solid porous titanium structure. The presence of a small amount of CaCl2in the interior also results in the coexistence of small Ti and CaO particles, forming a loose structure with uniform distribution.Keywords:CaCl2;calciothermic reduction;Ti2O3;microstructure;morphology;Ti particles