Directionally solidified in situ metal matrix composites. Part 2. Final report. [Co--Al--Cr, Co--Si--Nb, Co--Cr--Zr]

Technical Report · Mon Nov 01 04:00:00 EST 1976

OSTI ID:7218898

Haour, G; Mollard, F; Lux, B; Wright, I G

This work constitutes Part II of an alloy screening program to identify new eutectics based on Ni, Co and Fe suitable for the manufacture of directionally solidified turbine blades operating at up to 1150 C. During this Part II, thirteen alloy systems, selected for screening during Part I, have been experimentally investigated, leading to the identification of three eutectics of potential interest: Co-Al-Cr, Co-Si-Nb and Co-Cr-Zr. As a result of the overall program, Part I and Part II, a total of 9 eutectics have thus been found to meet the objectives of a melting point above 1200 C, a specific gravity below 9 g/cc and a reasonably low parabolic oxidation rate. These eutectics thus have, before any development, an oxidation resistance comparable or superior to the chromium free gamma/gamma-delta eutectic superalloy Ni-2.55 A1-21.75 Nb (wt %). It is therefore expected that an alloy optimization program would improve their oxidation behavior, as compared to the gamma/gamma-delta alloy with 6% chromium, presently the most advanced eutectic of this class of materials.

• Research Organization: Battelle Columbus Labs., OH (USA)
• OSTI ID: 7218898
• Report Number(s): AD-A-036385
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
360105 -- Metals & Alloys-- Corrosion & Erosion
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
COBALT ALLOYS
DENSITY
HIGH TEMPERATURE
MELTING POINTS
NIOBIUM ALLOYS
OXIDATION
PHYSICAL PROPERTIES
SILICON ALLOYS
TERNARY ALLOY SYSTEMS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
TURBINE BLADES
ZIRCONIUM ALLOYS