High Temperature Corrosion Behavior of Eutectic Structured NiAl-34Cr and NiAl-28Cr-6Mo Alloys Produced by Electric Current Activated Sintering

Point Defects in Nial Alloys under Pressure

We investigate the eeect of elevated pressures on the point defect ther-modynamics in NiAl alloys. A particular motivation for this study is due to the expected elimination of structural vacancies on the Al-rich side at high pressure. We employ the density functional theory to compute point defect energies as a function of pressure, which are in turn used as input to the Wagner-Schottky model. ...

High Temperature Internal Friction in NiAl Single Crystals

The internal friction of high-purity NiAl single crystals was investigated utilizing a low-frequency subresonance torsion a p m . Above lOOOK the damping increases strongly up to Q-' =0.3 at 1400K. The activation enthalpy of this viscoelastic relaxation depends on the composition and shows the highest value (2.8eV) for stoichiometric NiAl. The results are discussed in terms of diffusionantrolle...

High-temperature Corrosion Behavior of Iron Aluminide Alloys and Coatings

A multi-year effort has been focused on optimizing the long-term oxidation performance of ingot-processed (IP) and oxide-dispersion strengthened (ODS) Fe3Al and iron aluminidebased coatings. Based on results from several composition iterations, a Hf-doped alloy (Fe28Al-2Cr-0.05at.%Hf) has been developed with significantly better high temperature oxidation resistance than other iron aluminides. ...

Classification of corrosion defects in NiAl bronze through image analysis

Corrosion surface damage in the form of pitting and micro-cracks is observed in many metals. Cracks usually initiate from the pits and grow under cyclic stresses and eventually lead to material failure. An image analysis based on wavelet transforms and fractals was used to study the corrosion morphology of nickel aluminum bronze metal under varying corrosion conditions and applied stresses. Ima...

Sintering and Heat Treatment of Titanium Alloys by Pulsed Electric Current Sintering