Semi-solid forming of metal-matrix nanocomposites
AssigneeWisconsin Alumni Research Foundation
InventorsLih-Sheng Turng, Michael P. DeCicco, Xiaochun Li
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Abstract
A metal matrix nanocomposite is formed by heating a metal above its liquidus temperature, adding nanoparticles, and then agitating the mixture with high-frequency (and preferably ultrasonic) vibration. The mixture can then be cooled below the liquidus of the metal to a semisolid state, and placed in a mold to form it into some desired shape. The formed mixture can then be quenched or otherwise allowed to cool to provide an article in finished (or nearly so) form.
Claims25
A method of forming a metal matrix nanocomposite comprising the steps of:
- a. heating a metal above its liquidus temperature, thereby placing the metal in a liquid state;
- b. adding nanoparticles to the metal;
- c. vibrating the metal and nanoparticles;
- d. ceasing vibration while the metal is above its liquidus temperature;
- and
- e. forming the metal and nanoparticles into a desired shape by use of semi-solid casting when the metal is below its liquidus temperature but above its solidus temperature,
- wherein:
- (1) the metal lacks any grain refiners therein, and
- (2) the metal and nanoparticles, while below the metal's liquidus temperature, are not subjected to vibration, shearing, or other disruption apart from being formed into the desired shape.
A method of forming a metal matrix nanocomposite comprising the steps of:
- a. providing a mixture of nanoparticles and metal wherein the nanoparticles provide 0.25%-5.0% of the weight of the mixture, wherein the metal is above its liquidus temperature;
- b. vibrating the mixture when the metal is above its liquidus temperature;
- c. ceasing vibration before the metal drops below its liquidus temperature;
- d. flowing the mixture into a mold when the metal is below its liquidus temperature but above its solidus temperature, with the metal having between 40%-70% solid fraction, thereby molding the mixture into a desired shape via semi-solid casting,
- wherein:
- (1) the mixture does not contain grain refiners therein, and
- (2) the metal and nanoparticles, when the metal is below its liquidus temperature, are not subjected to vibration, shearing, or other disruption apart from being molded into the desired shape.
A method of forming a metal matrix nanocomposite comprising the steps of:
- a. adding nanoparticles to a metal while the metal is above its liquidus temperature;
- b. applying ultrasonic energy to the metal and nanoparticles while the metal is above its liquidus temperature;
- c. maintaining application of ultrasonic energy to the metal and nanoparticles until the metal is at or near its liquidus temperature;
- d. ceasing application of ultrasonic energy to the metal and nanoparticles before the metal drops below its liquidus temperature;
- and
- e. situating the metal and nanoparticles within a mold while the metal is below its liquidus temperature and above its solidus temperature, thereby molding the mixture into a desired shape via semi-solid casting,
- wherein the metal and nanoparticles, while below the metal's liquidus temperature:
- (1) do not contain grain refiners, and
- (2) are not subjected to vibration, shearing, or other disruption apart from being molded into the desired shape.
Dependencies are inferred from the claim text.