Processing, properties, and wear resistance of aluminides
Fully dense alloys based on Fe{sub 3}Al were produced by reaction synthesis from low cost elemental powders using hot pressing, hot isostatic pressing or Ceracon process. The reaction proceeds by outward spreading of a transient liquid phase from the initial aluminum particle site and precipitation of the compound phase from the liquid. Combustion synthesized material has a very fine grain size that is resistant to coarsening at high temperature because of a high density of fine oxides from the prior particle boundaries. The fine grain size results in approximately twice the yield strength in the reaction synthesized material compared to hot extruded pre-alloyed powder. Combustion synthesis has also been successfully applied to joining Fe{sub 3}Al and to forming coatings on carbon steel substrates. Combustion synthesis has been shown to be viable for fabricating trialuminides from elemental powder compacts. Al{sub 3}Ti, Al{sub 73}Ti{sub 24}Cr{sub 3} and Al{sub 67}Ti{sub 25}Cr{sub 8} were examined. Fully dense, homogeneous materials exhibiting an equiaxed grain structure were produced by conducting reaction and homogenization under pressure, or in a furnace at ambient pressure and subsequently densifying the porous preform by hot consolidation. The tetragonal DO{sub 22} structure was the primary reaction product for all compositions. Most of the Cr remained undissolved after reaction and a homogenization heat treatment at 1200C or above was used to put the Cr into solution and form the desired L1{sub 2} phase.
- Research Organization:
- EG and G Idaho, Inc., Idaho Falls, ID (United States)
- Sponsoring Organization:
- Department of the Interior, Washington, DC (United States)
- DOE Contract Number:
- AC07-76ID01570
- OSTI ID:
- 10150205
- Report Number(s):
- EGG-MS--10441; ON: DE93012186; CNN: Contract JO134035
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360101
360103
360105
ABRASION
ALUMINIUM ALLOYS
CHROMIUM ADDITIONS
COMBUSTION
CORROSION AND EROSION
EROSION
GRAIN SIZE
INTERMETALLIC COMPOUNDS
IRON BASE ALLOYS
MECHANICAL PROPERTIES
MICROSTRUCTURE
PREPARATION AND FABRICATION
SYNTHESIS
TENSILE PROPERTIES
TITANIUM ALLOYS
WEAR RESISTANCE