Niobium as a protective barrier in molten metals

• US 8,844,897 B2
• Filed: 03/04/2009
• Issued: 09/30/2014
• Est. Priority Date: 03/05/2008
• Status: Expired due to Fees

• Current Assignee: Southwire Company
• Original Assignee: Southwire Company
• Inventors: Rundquist, Victor F., Gill, Kevin S.
• Primary Examiner(s): BODAWALA, DIMPLE N
• Application Number:
  US12/397,534
• Publication Number:
  US 20090224443A1
• Time in Patent Office: 2,036 Days
• Field of Search: 249/114.1, 249/115, 249/116, 249/134, 249/135, 106/38.2, 106/38.22, 106/38.9, 164/122, 164/138, 164/411, 164/443, 164/DIG.6, 164/DIG.15, 164/418, 164/459
• US Class Current: 249/114.1
• CPC Class Codes: B06B 3/00 Methods or apparatus specially adapted for transmitting mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
• CPC Class Codes: B22D 11/004 Copper alloys
• CPC Class Codes: B22D 11/04 into open-ended moulds B22D11/06, B22D11/07 take precedence; plants for continuous casting, e.g. for upwardly drawing the strand B22D11/14
• CPC Class Codes: B22D 11/059 Mould materials or platings
• CPC Class Codes: B22D 25/02 by its peculiarity of shape; of works of art cylinders, pistons B22D15/02
• CPC Class Codes: C22C 9/00 Alloys based on copper

Abstract

Devices may be in contact with molten metals such as copper, for example. The devices may include, but are not limited to, a die used for producing articles made from the molten metal, a sensor for determining an amount of a dissolved gas in the molten metal, or an ultrasonic device for reducing gas content (e.g., hydrogen) in the molten metal. Niobium may be used as a protective barrier for the devices when they are exposed to the molten metals.

Claims

1. A die having an entrance on one side and an exit on another side, the die comprising:

an outer layer configured to cause heat to be transferred from molten metal into a surrounding atmosphere such that the die is configured to form a solid article from the molten metal; and

an inner layer configured to provide an oxygen barrier for the outer layer, wherein the inner layer is configured to provide the oxygen barrier for the outer layer when the die is exposed to a temperature of about 1100°

C., and wherein the inner layer comprises elemental niobium;

wherein the outer layer comprises graphite; and

wherein a thickness of the inner layer is less than about 10 microns.

4. The die of claim 1, wherein the thickness of the inner layer comprising elemental niobium is in a range from about 1 to about 4 microns.

2. A die having an entrance on one side and an exit on another side, the die configured for efficient heat transfer and increased die lifetime, the die comprising:

an outer layer comprising graphite and configured to cause heat to be transferred from molten metal into a surrounding atmosphere such that the die is configured to form a solid article from the molten metal; and

an inner layer comprising elemental niobium, the inner layer having a thickness in a range from about 1 to about 10 microns.

3. The die of claim 2, wherein the thickness of the inner layer comprising elemental niobium is in a range from about 3 to about 6 microns.

5. The die of claim 2, wherein the thickness of the inner layer comprising elemental niobium is in a range from about 1 to about 3 microns.

6. A die having an entrance on one side and an exit on another side, the die comprising:

graphite portions, the graphite portions configured to cause heat to be transferred from molten metal into a surrounding atmosphere such that the die is configured to form a solid article from the molten metal; and

a coating comprising elemental niobium over the graphite portions,

the coating having a thickness in a range from about 1 to about 10 microns.

7. The die of claim 6, wherein the thickness of the coating comprising elemental niobium is in a range from about 2 to about 8 microns.

8. The die of claim 6, wherein the thickness of the coating comprising elemental niobium is in a range from about 3 to about 6 microns.

9. The die of claim 6, wherein the thickness of the coating comprising elemental niobium is in a range from about 1 to about 4 microns.

10. A die having an entrance on one side and an exit on another side, the die configured to form solid articles from molten metals, the die comprising:

an outer layer comprising graphite; and

an inner layer comprising elemental niobium, the inner layer having a thickness in a range from about 2 to about 8 microns.