Electrical contact alloy for vacuum contactors

Patent metadata

Field	Value
Publication number	US-10804044-B2
Application number	US-201916585637-A
Country	US
Kind code	B2
Filing date	Sep 27, 2019
Priority date	Dec 13, 2016
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

An improved electrical contact alloy, useful for example, in vacuum interrupters used in vacuum contactors is provided. The contact alloy according to the disclosed concept comprises copper particles and chromium particles present in a ratio of copper to chromium particles of 2:3 to 20:1 by weight. The electrical contact alloy also comprises particles of a carbide, which reduces the weld break strength of the electrical contact alloy without reducing its interruption performance.

First claim

What is claimed is:

1. A method of making an electrical contact for use in a vacuum interrupter comprising:
milling carbide particles to a desired size;
providing copper and chromium particles that are larger in size than the milled carbide particles;
mixing the milled carbide particles with the copper and chromium particles, present in a ratio of copper to chromium particles at 2:3 to 20:1 by weight;
pressing the mixture into a compact; and,
heating the compact to a temperature appropriate to a sintering process selected from the group consisting of solid state sintering, liquid phase sintering, spark plasma sintering, vacuum hot pressing, and hot isostatic pressing, such that the compact attains the properties suitable for use as a vacuum interrupter contact.

2. The method recited in claim 1 further comprising forming an electrical contact of a desired configuration by machine shaping a dense blank.

3. The method recited in claim 1 further comprising adding to the mixture a sinter activation element to increase the compact density upon sintering.

4. The method recited in claim 3 wherein the sinter activation element is selected from the group consisting of cobalt, nickel, nickel-iron, iron aluminide, and combinations thereof.

5. The method recited in claim 1 wherein the temperature in the sintering process is between 1085° C. and 1200° C.

6. The method recited in claim 1 wherein the carbide particles are selected from the group consisting of silicon carbides and metal carbides.

7. The method recited in claim 6 wherein the metal carbides are selected from the group consisting of tungsten carbide, molybdenum carbide, vanadium carbide, chromium carbide, niobium carbide, tantalum carbide, titanium carbide, and hafnium carbide.

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Campbell Louis Grant
• Balasubramanian Ganesh Kumar
• Rosenkrans Benjamin Alex

Classifications

• B22F1/09

  Mixtures of metallic powders · CPC title

• C22C32/0052

  only carbides · CPC title

• B22F2301/20

  Refractory metals · CPC title

• B22F3/15

  Hot isostatic pressing · CPC title

• H01H1/0206 Primary

  containing as major components Cu and Cr · CPC title