Method of forming oxide dispersion strengthened alloys
A method of forming an oxide-dispersion strengthened alloy and a method for forming an oxide-alloy powder where the oxide-nanoparticles are evenly distributed throughout the powder. The method is comprised of the steps of forming an oxide-nanoparticles colloid, mixing the oxide-nanoparticles colloid with alloy-microparticles forming an oxide-alloy colloid, drying the oxide-alloy colloid solution to form an oxide-alloy powder, applying pressure to the oxide-alloy powder, and heating the oxide-alloy powder to a sintering temperature. The oxide-nanoparticles are sized to be between 1-10 nanometers in diameter. The ratio of oxide-nanoparticles to alloy-microparticles should be 1-5% by weight. Heating of the oxide-alloy powder can use a spark plasma sintering process.
1. A method of forming an oxide-dispersion strengthened alloy comprising the steps:
a. mixing a first quantity of oxide-nanoparticles with a liquid forming a colloid of oxide-nanoparticles, wherein the oxide-nanoparticles are 1-5 nanometers in the largest dimension;
b. mixing the colloid of oxide-nanoparticles with a second quantity of alloy-microparticles forming an oxide-alloy colloid, wherein the oxide-nanoparticles are substantially uniformly distributed throughout the colloid, and wherein substantially all of the oxide-nanoparticles adhere to the alloy-microparticles and not to the oxide-nanoparticles;
c. drying the oxide-alloy colloid, forming an oxide-alloy powder; and
d. heating the oxide-alloy powder to a sintering temperature.
2. The method of claim 1 , wherein the first quantity of oxide-nanoparticles is between 1% and 5% by weight of the oxide-alloy powder.
3. The method of claim 1 , wherein the alloy-microparticles contain nickel.
4. The method of claim 1 , wherein the alloy-microparticles contain greater than 50 wt % nickel.
5. The method of claim 2 , wherein the first quantity of oxide-nanoparticles is selected from at least one of Alumina, Silica, and Yttria.
6. The method of claim 2 , further comprising the step of applying pressure to the oxide-alloy powder.
7. The method of claim 6 , wherein the pressure is applied axially with of a force of between 30 and 50 tons per square inch.
8. The method of claim 6 , wherein the heating of the alloy powder is performed by a spark plasma process.
9. The method of claim 8 , wherein the pressure is applied to the oxide-alloy powder with a graphite die.
10. The method of claim 1 , further comprising the step of ball-milling the oxide-alloy powder.
11. A method of forming an oxide-alloy powder comprising the steps:
a. mixing a first quantity of oxide-nanoparticles with a liquid forming a colloid of oxide-nanoparticles, wherein the oxide-nanoparticles are 1-5 nanometers in the largest dimension;
b. mixing the colloid of oxide-nanoparticles with a second quantity of alloy-microparticles forming an oxide-alloy colloid, wherein the oxide-nanoparticles are substantially uniformly distributed throughout the colloid, and wherein substantially all of the oxide-nanoparticles adhere to the alloy-microparticles and not to oxide-nanoparticles; and
c. drying the oxide-alloy colloid, forming an oxide-alloy powder.
12. The method of claim 11 , wherein the first quantity of oxide-nanoparticles is between 1% and 5% by weight of the oxide-alloy powder.
13. The method of claim 12 , further comprising the step of ball-milling the oxide-alloy powder.
14. The method of claim 12 , wherein the first quantity of oxide-nanoparticles is selected from at least one of Alumina, Silica, and Yttria.