J Mater Sci Technol ›› 2007, Vol. 23 ›› Issue (03): 367-372.

• Research Articles • Previous Articles     Next Articles

A new process for titanium aluminides production from TiO2

A.R.Kamali, H.Razavizadeh, S.M.M.Hadavi   

  1. Department of Materials and Metallurgy Engineering, IUST University, Tehran, Iran...
  • Received:2006-06-27 Revised:2006-10-11 Online:2007-05-28 Published:2009-10-10
  • Contact: A.R.Kamali

Abstract: This paper describes a new process for producing titanium aluminides, in particular TiAl, from TiO2 raw material. On the basis of obtained results, the non-completed reaction of TiO2 with Al and Ca in a special reaction vessel results in the production of granulates of titanium aluminides especially Ti3Al and other Ti-Al phases as the metallic product and Ca12Al14O33 as the non-metallic product. By adding KClO4 in the mixture, a nearly completed reaction can be carried out. The products of this reaction are titanium aluminide particularly TiAl as the metallic part and CaAl4O7 (grossite) as the non-metallic slag part. Both product and slag are produced in a separated form. This process, called KRH-method is described in this article. The scanning electron microscopic microstructure of metallic part of the product shows different phases: the matrix phase is TiAl, where the needle form precipitation is TiAl2 and the plate form precipitation includes TiAl and Ti3Al phases. The microstructure of the remelted metallic part indicates dendritic phase with a lamellar structure comprising of TiAl and Ti3Al phases. The interdendritic phase of TiAl is also seen.

Key words: Titanium aluminide, Titanium dioxide, Grossite, KRH process