Effect of nitrogen addition on microstructures and mechanical propeties of TiAl based alloys
(State Key Laboratory for Powder Metallurgy; Chntral South University of Technology; Changsha 410083; P. R. China)
Abstract: Through adding 0 % 3 % (mole fraction) nitrogen in cast TiAl based alloys, it was found that colony size in cast condition decreased from 600 um to 58 um with nitrogen content increasing from zero to 1%and then decreased slowly with further increase of nitrogen content, tensile strength increased with nitrogen content; but comparing to the value of the mother alloy, tensile elongation at room temperature decreased in the alloy with 0. 5 % nitrogen, then recovered in the alloy with 1% nitrogen.
Key words: TiAl based alloys; microstructure; nitrogen addition; grain refinement