Quantitative phase analysis in the Ti–Al–C ternary system by X-ray diffraction

Materials in the Ti–Al–C ternary system commonly contain three coexisting phases, Ti 3 AlC 2 , Ti 2 AlC, and TiC. Quantitative phase analysis in this ternary system was investigated using X-ray diffraction. First, nonoverlap diffraction peaks were selected: the (002) peak at 2 θ =9.5° for Ti 3 AlC 2 ( I ∕ I 0 =26.5), the (002) peak at 2 θ =13.0° for Ti 2 AlC ( I ∕ I 0 =39), and the (111) peak at 2 θ =35.9° for TiC ( I ∕ I 0 =78), respectively. Then, based on the mixing-sample method without internal standards, a set of equations was derived for determining the amounts of Ti 3 AlC 2 , Ti 2 AlC, and TiC in a sample using the intensities of the selected diffraction peaks. Finally, the applicability and error sources for this method were investigated. The method is simple and straightforward, and is applicable to the entire Ti–Al–C ternary system, since the derivation of this equation group is self-checking.