The mechanical properties of γ-base titanium aluminides depend strongly on the microstructural parameters. γ-base titanium aluminides with fully lamellar microstructure possess excellent fracture properties compared with other microstructures. Binary Ti-46Al and niobium alloyed Ti-47 Al-3Nb were used to investigate the fracture behavior of γ-base titanium aluminides. The addition of niobium refined the grain size of the material and thereby increased the flexural strength, but had no influence on the fracture toughness. The fatigue crack growth behavior (ΔK vs. da dN) of the niobium alloyed material was superior to that of the binary material. Roughness-induced crack closure plays a significant role in the lamellar microstructure material. Toughening due to microcracks, crack branching, and crack bridging by uncracked ligaments was also observed in the test materials.
|Number of pages||8|
|Journal||Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing|
|Publication status||Published - 1994 Jul 15|