Experimental Study on the Preparation of Ti-Al Based Alloy by Aluminothermic Reduction-Vacuum Electromagnetic Levitation Refining of Waste Denitration Catalyst

Experimental study on the preparation of Ti-Al based intermetallic alloy from selective catalytic reduction(SCR) Ti-based denitration catalyst was first conducted by using aluminothermic reduction followed with the vacuum electromagnetic levitation melting.Using SEM and XRD analyses,it is found that the alloy is mainly composed of TiAl₂,Ti₅Si₃ and TiAl phases while the impurities mostly exist as the form of oxides and carbides.With the refining of the alloy,the composition of Ti-Al compound changes from Ti-rich to Al-rich titanium aluminide,and the impurities content decreases gradually with more than 85% of the total impurity removal rate after three times of refining.Finally,the hardness test was performed and it shows increase tendency with increase of refining times.This is due to the increase of TiAl₂ phase with high hardness and the decrease of TiAl phase with low hardness.