Study of structural evolution and thermal stability of ball-milled Ti-Al and Ti-Al-Mn-Nb nanocrystalline powders

Abstract

Binary Ti-Al and ternary Ti-Al-Mn-Nb alloys have been prepared by high-energy planetary ball milling using elemental powders. The structural evolution of the ball-milled powders was monitored using X-ray diffractometry. It was found that the milling product in the binary system was different from that of the ternary system. In the binary system, the face-centre-cubic phase was the final product. Addition of Mn and Nb was observed to favour the formation of an amorphous phase. The phase transformation of the ball milled powders was studied. After thermal treatment, stoichiometric L10-TiAl intermetallic compound could be obtained. The effects of Mn and Nb additions on the transformation path and thermal stability of the alloy have been discussed.