Accession Number:

ADA242741

Title:

High Temperature Mass Spectrometry of Liquid Nickel-Aluminum Alloys at 2000 K

Descriptive Note:

Technical rept.

Corporate Author:

MATERIALS RESEARCH LABS ASCOT VALE (AUSTRALIA)

Personal Author(s):

Report Date:

1991-05-01

Pagination or Media Count:

31.0

Abstract:

The activity of nickel at 2000 K shows large negative deviations from Raoults law, which is indicative of the strong attraction between the nickel and aluminium atoms. The role of container interactions in affecting thermodynamic parameters derived from Knudsen cell measurements is highlighted, and inconsistencies in earlier investigations are discussed. Study of the thermodynamic properties of nickel aluminum alloys is important in providing information on the stability and phase relationships in these alloys, which find numerous applications in high-temperature materials of defense interest. Yttrium, Nickle, Aluminum phase precipitation in nickel base superalloys. This imparts high-temperature strength, necessary for components in the hot end of gas-turbine engines. Diffusion aluminide coatings used to protect nickel-base turbine aerofoils against oxidation and corrosion rely on the formation of the Beta-NiAl phase. This provides a source of aluminium for growth and repair of the protective scale of alumina which forms at high temperature under oxidizing conditions.

Subject Categories:

  • Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE