The effect of Nb addition on microstructure and mechanical properties of Ni3(Si,Ti) alloy

Research paper by T. Takasugi, M. Yoshida

Indexed on: 01 Feb '01Published on: 01 Feb '01Published in: Journal of Materials Science


The alloying behavior, the microstructure and the high-temperature tensile properties of the Nb-added Ni3(Si,Ti) alloys were investigated. The solubility limit of Nb element in the L12 Ni3(Si,Ti) phase at 1273 K was shown to be approximately 2.7 at%, and thermodynamically discussed. The second-phases (dispersions) formed beyond the solubility limits were identified as D0a-type Ni3Nb and Ni12Si4TiNb2 compounds, and contained some lattice defects with incoherency with the L12 Ni3(Si,Ti) matrix. The Nb-containing second-phase dispersions in the L12 Ni3(Si,Ti) phase matrix resulted in strengthening over a wide range of temperature, and also an improvement of the high-temperature tensile elongation.