Effect of Ternary Additions on the Room Temperature Lattice Parameter of Ni3Al

Abstract

The room temperature lattice parameters of Ni3Al alloys with and without ternary additions are measured by X-ray diffraction. The lattice parameters of Ni3Al phase alloys increase with Al concentration. The addition of B, Hf, Zr, and Ti to Ni3Al increases the lattice parameter and Si additions decrease it. The results obtained are discussed in terms of crystal structure and atomic sizes. The lattice strain produced by the addition of Hf and Zr is found to be 0.09 and 0.11, respectively which is approximately three times less than that of boron addition (0.30), suggesting the substitutional nature of Hf and Zr and the interstitial nature of boron addition.