Manufacture of tungsten monocarbide (WC) spherical powder

Patent metadata

Field	Value
Publication number	US-11072533-B2
Application number	US-201716318974-A
Country	US
Kind code	B2
Filing date	Jul 21, 2017
Priority date	Jul 21, 2016
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

Powder metallurgy, in particular production of tungsten monocarbide spherical powders, which is a major component of metalloceramic hard alloys used for manufacture of tools, drill bits, steel alloying, wear-resistant coating cladding at elements operating in intensive wear conditions. The method includes melting of the starting material, and melt atomization with forming of spherical powder. As starting material a tungsten monocarbide grit is used. Melting and atomization of the material is implemented by continuous filling of grit into a rotating crucible of a centrifugal atomization device under an inert atmosphere and melting it by a plasma arc. After that an annealing of the obtained powder is made at a temperature of 1200-1400° C. during a time necessary for W 2 C breakup with subsequent cooling of the powder in a furnace. And, the production of tungsten monocarbide spherical powder with WC content of more than 70%.

First claim

The invention claimed is:

1. A method for the manufacture of tungsten monocarbide (WC) spherical powder said method comprising the steps of:
initial melting of a starting material, and subsequent melt atomization with forming of spherical powder
wherein a grit of tungsten monocarbide is used as the starting material, melting and atomization of the starting material is performed by continuous filling of grit into a rotating crucible of a centrifugal atomization device under an inert atmosphere and melting by plasma arc to form a powder comprising WC, W 2 C, and C, and after that an annealing of the powder is made at a temperature of 1200-1400° C. during a time necessary for W 2 C breakup and subsequent cooling of the powder in a furnace.

2. The method according to claim 1 , wherein the starting material is a grit of tungsten monocarbide WC with a particle size in the interval 20-80 μm.

3. The method according to claim 1 , wherein the annealing of the obtained powder is performed during 1.5-2 hours.

4. The method according to claim 1 , wherein a powder with particle size from 10 μm to 2.5 mm is produced.

5. The method according to claim 1 , wherein the inert atmosphere comprises at least one gas selected from the group consisting of nitrogen, argon, and helium.

Assignees

• Hoeganaes Ab Publ

Inventors

• Shevchenko Ruslan Alekseevich
• Vakhrushin Alexander Yurievich
• Chukanov Andrey Pavlovich

Classifications

• B22F9/082

  atomising using a fluid (using centrifugal force B22F9/10) · CPC title

• B22F2009/0848

  Melting process before atomisation · CPC title

• B22F9/10

  using centrifugal force · CPC title

• C01P2002/60

  Compounds characterised by their crystallite size · CPC title

• C01B32/949 Primary

  Tungsten or molybdenum carbides · CPC title