Hot Ductility Loss in a Fe-Ni-Based Superalloy

Hot Ductility Loss in a Fe-Ni-Based Superalloy

High temperature tensile tests have been conducted on samples of a Fe-Ni based superalloy, Incoloy A-286, and significant ductility loss has been observed at 1220 °C. Titanium-rich, thin-film-like phase has been found on the inter-granular facets of fracture surfaces. It appears that sulfur content of Ti-rich phase was higher than that of the matrix. At 1220 °C, liquation of Ti-rich phases has ...

Study of a New Type High Strength Ni-Based Superalloy DZ468 with Good Hot Corrosion Resistance

Extreme Ductility at the Nanoscale in Fe-based Alloys

A novel method for preparing and testing bending specimens in-situ the TEM has been developed. This method provides high visibility of the crack front and its associated plastic zone. This is significant because energy release rates can now be calculated at many points throughout the test based on crack tip opening displacement (CTOD), crack opening angle (COA), and crack advance. Further refin...

Plasticity of nanocrystalline alloys with chemical order: on the strength and ductility of nanocrystalline Ni–Fe

Plastic deformation and alloying of nanocrystalline Ni-Fe is studied by means of atomic scale computer simulations. By using a combination of Monte-Carlo and molecular dynamics methods we find that solutes have an ordering tendency even if grain sizes are in the nanometer regime, where the phase field of the ordered state is widened as compared to larger grain sizes. Tensile testing of disorder...

Creep of Ni-Al and Ni-Cr-Al Superalloy Foams

The steady-state creep rate of Ni-base metallic foams, with superalloy composition (in wt. pct) Ni7.8∼9.1Al (relative density, ρ = 2.5-2.6) and Ni-13.5∼16.6Cr-5.1∼8.9Al (ρ = 2.8∼3.0), was measured under a range of temperatures (680∼825°C) and applied stresses (0.1∼0.3 MPa), and compared with that of NiAl intermetallic foams (ρ = 5.3). The stress exponent and activation energy are within the exp...