Claims
- 1. A method for simultaneously synthesizing and densifying nanocrystalline materials, said method comprising:(a) compacting nano-scale particles of said solid particular reactants into a green body in a preselected stoichiometric ratio; and (b) simultaneously (i) passing an electric current through said green body of sufficient intensity to cause Joule heating of said green body to a temperature at which synthesis of said reaction product from said solid particulate reactants is initiated and (ii) applying to said green body a pressure sufficiently high to cause said reaction product to have a relative density substantially greater than that of said green body.
- 2. A method in accordance with claim 1 further comprising forming said nano-scale particles by milling particles of sizes about 1 micron or greater in diameter.
- 3. A method in accordance with claim 1 in which said nano-scale particles are less than about 200 nm in diameter.
- 4. A method in accordance with claim 1 in which said nano-scale particles are from about 10 nm to about 200 nm in diameter.
- 5. A method in accordance with claim 1 in which said electric current is from about 1,000 Å to about 2,500 Å.
- 6. A method in accordance with claim 1 in which said electric current is from about 1,200 Å to about 1,800 Å.
- 7. A method in accordance with claim 1 in which said pressure is from about 30 MPa to about 300 MPa.
- 8. A method in accordance with claim 1 in which said pressure is from about 50 MPa to about 200 MPa.
- 9. A method in accordance with claim 1 in which said pressure is from about 70 MPa to about 110 MPa.
GOVERNMENT RIGHTS
This invention was made with Government support under Contract No. DAAH04-95-0353, awarded by the Army Research Office. The Government has certain rights in this invention.
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|
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