Method For Making Metal-Nanostructured Carbon Composites

Patent metadata

Field	Value
Publication number	US-2019381563-A1
Application number	US-201816009897-A
Country	US
Kind code	A1
Filing date	Jun 15, 2018
Priority date	Jun 15, 2018
Publication date	Dec 19, 2019
Grant date	—

Abstract

A method for making covetic metal-nanostructured carbon composites or compositions is described herein. This method is advantageous, in that it provides substantially oxygen-free covetic materials and allows precise control of the composition of the covetic material to be produced. The method comprises introducing carbon into a molten metal in a heated reactor under low oxygen partial pressure, while passing an electric current through the molten metal. The reactor is heated at a temperature sufficient to form a network of nanostructured carbon within a matrix of the metal. After heating the covetic material is recovered from the reactor.

First claim

1 . A process for preparing a covetic metal-carbon composite material comprising the steps of:
(a) introducing carbon into a molten metal in a heated reactor under an atmosphere comprising a partial pressure of oxygen of not more than about 0.1 Torr, while passing an electric current through the molten metal at a current density of about 10 to about 100 amperes per square centimeter by a pair of electrodes contacting the molten metal and in circuit with an electrical power source; wherein the molten metal fills the reactor to a level such that an exposed surface of the metal is located about one third to one half of the distance from an internal height in the reactor; the carbon is introduced at or below the exposed surface of the molten metal with mixing to distribute carbon within the molten metal; and the reactor is heated at a temperature above the melting point of the metal sufficient to form a network of nanostructured carbon within a matrix of the metal; and (b) recovering the resulting covetic metal-carbon composite material from the reactor.

2 . The process of claim 1 , wherein the metal comprises at least one metal selected from the group consisting of copper, aluminum, silver, gold, platinum, iron, lead, zinc, silicon, tin, and nickel.

3 . The process of claim 1 , wherein the metal comprises copper; and the reactor is heated at a temperature of at least about 1150° C.

4 . The process of claim 1 , wherein the metal comprises aluminum; and the reactor is heated at a temperature of at least about 700° C.

5 . The process of claim 1 , wherein the carbon is a particulate carbon material.

6 . The process of claim 1 , wherein the carbon comprises graphite.

7 . The process of claim 1 , wherein the reactor is composed of graphite or a ceramic material.

8 . The process of claim 1 , wherein the partial pressure of oxygen is in a range of about 0.001 Torr to about 0.1 Torr.

9 . The process of claim 1 , wherein the carbon is introduced into the reactor through a feed tube that passes through a shield that extends over at least 50% of the area of the exposed surface of the molten metal.

10 . The process of claim 1 , wherein the mixing is non-vortexing mixing.

11 . The process of claim 1 , wherein the total amount of carbon introduced into the metal comprises about 0.1 to about 10 percent by weight based on the total weight of the metal and carbon in the reactor.

12 . A process for preparing a covetic metal-carbon composite material comprising the steps of:
(a) introducing carbon into a molten metal in a heated graphite reactor while passing an electric current through the molten metal at a current density of about 10 to about 100 amperes per square centimeter by a pair of graphite electrodes contacting the molten metal and in circuit with an electrical power source; wherein the molten metal fills the reactor to a level such that an exposed surface of the metal is located about one third to one half of the distance from an internal height in the reactor; the carbon is introduced at or below the exposed surface of the molten metal utilizing non-vortexing mixing to distribute carbon within the molten metal; and the reactor is heated at a temperature above the melting point of the metal sufficient to form a network of nanostructured carbon within a matrix of the metal; and (b) recovering the resulting covetic metal-carbon composite material from the reactor; wherein the reactor is open to ambient air, and graphite from the electrodes, the reactor, the carbon, or any combination thereof, reacts to form a reducing atmosphere comprising carbon monoxide over the exposed surface of the molten metal; and the metal comprises at least one metal selected from the group consisting of aluminum, gold, silver, lead, zinc, silicon, tin, and nickel.

13 . The process of claim 12 , wherein the metal is aluminum, and the reactor is heated at a temperature of at least about 700° C.

14 . The process of claim 12 , wherein the carbon is graphite powder.

15 . A process for preparing a covetic metal-carbon composite material comprising the steps of:
(a) heating a mixture of carbon and a metal in a reactor under an atmosphere comprising a partial pressure of oxygen of not more than about 0.1 Torr, and at a temperature above the melting point of the metal sufficient to melt the mixture and form a network of nanostructured carbon within a matrix of the metal; (b) passing an electric current through the melted metal at a current density of about 10 to about 100 amperes per square centimeter through a pair of electrodes contacting the mixture and in circuit with an electrical power source; and (c) recovering the resulting covetic metal-carbon composite material from the reactor; wherein the metal comprises at least one metal selected from the group consisting of copper, aluminum, silver, gold, platinum, iron, lead, zinc, silicon, tin, and nickel; and the amount of carbon in the mixture comprises about 0.1 to about 10 percent by weight of the total weight of the metal and carbon in the mixture.

16 . The process of claim 15 , wherein the carbon comprises graphite; and
(a) the metal comprises copper; and the reactor is heated at a temperature of at least about 1150° C.; or (b) the metal comprises aluminum; and the reactor is heated at a temperature of at least about 700° C.

17 . The process of claim 15 ; wherein the mixture is heated under an atmosphere of ultra-pure helium.

18 . A covetic metal-carbon composite material produced by the process of claim 1 .

19 . A covetic metal-carbon composite material produced by the process of claim 12 .

20 . A covetic metal-carbon composite material produced by the process of claim 15 .

Assignees

• Uchicago Argonne Llc

Inventors

• Balachandran Uthamalingam
• Ma Beihai
• Lee Tae H
• Dorris Stephen E
• Forrest David R

Classifications

• B01J19/0066

  Stirrers (mixing per se B01F) · CPC title

• B01J19/0013

  Controlling the temperature of the process · CPC title

• B22F1/054

  Nanosized particles · CPC title

• B22F1/056

  Submicron particles having a size above 100 nm up to 300 nm · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title