Formation of structural intermetallics by reactive metal penetration of Ti and Ni oxides and aluminates
- Univ. of New Mexico, Albuquerque, NM (United States). Chemical and Nuclear Engineering Dept.
- Sandia National Labs. Albuquerque, NM (United States)
- Lawrence Berkeley Lab., CA (United States)
Alumina-aluminum composites can be prepared by reactive metal penetration (RMP) of mullite by aluminum. The process is driven by a strong negative free energy for the reaction (8 + x)Al + 3Al{sub 6}Si{sub 2}O{sub 13} {yields} 13Al{sub 2}O{sub 3} + 6Si + xAl. Thermodynamic calculations reveal that titanium oxide, aluminum titanate, nickel oxide, and nickel aluminate all have a negative free energy of reaction with aluminum from 298 to 1,800 K, indicating that it may be possible to form alumina-intermetallic composites by reactions of the type (2 + x)Al + (3/y) MO{sub y} {yields} Al{sub 2}O{sub 3} + Al{sub x}M{sub 3/y}. Experiments revealed that aluminum reacts with titanium oxide, nickel oxide, and nickel aluminate, but not aluminum titanate, at 1,673 K. Reaction with the stoichiometric amount of aluminum (x = 0) leads to the formation of alumina and either titanium or nickel. In some cases, reactions with excess aluminum (x > 0) produce intermetallic compounds such as TiAl{sub 3} and NiAl.
- Research Organization:
- Sandia National Laboratory
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 282254
- Report Number(s):
- CONF-950201--
- Journal Information:
- Metallurgical Transactions, A, Journal Name: Metallurgical Transactions, A Journal Issue: 8 Vol. 27; ISSN 0360-2133; ISSN MTTABN
- Country of Publication:
- United States
- Language:
- English
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