Synthesis of bulk and reinforced nickel aluminides by reactive infiltration

Journal Article · Fri Oct 01 00:00:00 EDT 1993 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02648590· OSTI ID:5731486

Dunand, D C; Mortensen, A ^[1]; Sommer, J L ^[2]

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1. Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Materials Science and Engineering
2. Technical Research Associates, Salt Lake City, UT (United States)

Preforms of nickel powder or nickel/alumina powder blends were infiltrated with molten aluminum to produce nickel aluminides. Application of a pressure of 3.6 and 6.9 MPa on the melt allowed infiltration of preforms with nickel powder particles between 5 and 15 [mu]m in diameter, which could not be infiltrated under the sole action of capillary forces. By varying the initial preform temperature from 705 C to 280 C, the diameter of nickel powder particles from 15 to 150 [mu]m, and the volume fraction of alumina from 0 to 34 vol pct, pressure-infiltrated samples with large variations in the extent of reaction between nickel and aluminum were produced. The range of microstructure extended from fully reacted nickel aluminide to essentially unreacted nickel/aluminum samples containing low levels of final porosity. In particular, it was found that reducing the initial preform temperature below the melting point of aluminum results in a reduction of the rate and extent of aluminide formation, allowing, in turn, reduction of macrosegregation within the resulting infiltrated material.

• OSTI ID: 5731486
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Journal Name: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States) Vol. 24A:10; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101* -- Metals & Alloys-- Preparation & Fabrication
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
ELEMENTS
FABRICATION
HEAT TREATMENTS
IMPREGNATION
INTERMETALLIC COMPOUNDS
METALS
MICROSTRUCTURE
NICKEL
NICKEL ALLOYS
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
POWDERS
PRESSURIZATION
SIZE
TRANSITION ELEMENTS