Niksirat S, Raygan S, Moradi Ghiassabadi S. MECHANO-THERMAL REDUCTION OF HEMATITE AND ANATASE MIXTURE BY TWO DIFFERENT FORMS OF CARBON AS REDUCTANT FOR IN-SITU PRODUCTION OF Fe-T iC - NANO CRYSTALLINE COMPOSITE. IJMSE 2015; 12 (2) :56-70
URL:
http://ijmse.iust.ac.ir/article-1-803-en.html
Abstract: (27952 Views)
In this research, two different carbonaceous materials (Graphite:G and Petrocoke:P) were separately
compared in terms of the carbothermic reduction of hematite and anatase in order to synthesize Fe-TiC nanocrystalline composite by mechanically activated sintering method. Powders were activated in a planetary high-energy
ball mill under argon atmosphere for 0, 2, 5, 10,and 20 h. Then, the activated powders were analyzed by XRD and
SEM to investigate phase constituents and microstructure of the mixtures. Results proved that Fe
2
O
3
and TiO
2
were not
reduced by carbonaceous materials even after 20h of milling. SEM investigations showed that G-mixture was more
homogenous than P-mixture after 20h of milling, meaning that graphite-anatase-hematite was mixed satisfactorily.
Thermogravimetry analysis was done on 0 and 20h milled powders. TG and DTG curves showed that mechanical
activation led to almost 300°C decrease in the reduction temperature of hematite and anatase in both mixtures. In the
next step, the powders were sintered in a tube furnace under argon atmosphere. In the G-mixture, anatase was reduced
to titanium carbide at 1100°C but, in the P-mixture, temperature of 1200°C was essential for completely reducing
anatase to titanium carbide.Results of phase identification of the sintered powders showed that anano-crystalline ironbased composite with titanium carbide, as the reinforcement was successfully synthesized after 20 h high-energy
milling of the initial powders and subsequent sintering occurred at 1200˚C for 1h
Type of Study:
Research Paper |