Water-atomized spherical metal powders and method for producing the same

• US 6,221,125 B1
• Filed: 10/12/1995
• Issued: 04/24/2001
• Est. Priority Date: 06/22/1994
• Status: Expired due to Term

• Current Assignee: Mitsubishi Steel Manufacturing Company Limited
• Original Assignee: Mitsubishi Steel Manufacturing Company Limited
• Inventors: Usui, Hiroshi, Soda, Yuji, Tokuyama, Yukio
• Primary Examiner(s): KASTLER, SCOTT R
• Application Number:
  US08/542,399
• Time in Patent Office: 2,021 Days
• Field of Search: 753/42, 752/55
• US Class Current: 75/342
• CPC Class Codes: B22F 1/065 Spherical particles
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps

Abstract

A water-atomized metal powder having a spherical particle shape, an average particle size of 25 μm or less and a tap density ratio of 50-60%. The spherical powder is produced by forming non-spherical metal particles, which have been produced from molten metal by water-atomization, into spherical particles using a high speed gas current which causes high speed collisions to occur between said particles and between said particles and a collision body. The thus obtained spherical metal powder is particularly suitable for injection molding since and, by using the powder, the blending proportion of organic binder used in injection molding can be reduced and high strength debound bodies can be obtained.

Claims

1. A water-atomized metal powder having a spherical particle shape, an average particle size of 10-25 microns and a tap density ratio of 50-60%.

3. The water-atomized metal powder of claim 1, wherein the tap density ratio is from 50-54.2%.

2. A method for producing water-atomized spherical metal powder, the method comprising forming metal particles of non-spherical shapes from molten metal by water-atomization, and subjecting the metal particles to a high speed gas stream to cause high speed collisions to occur between said particles and between said particles and a collision target to form spherical particles having an average particle size no greater than 25 μ

m and a tap density ratio of from 50-60%.

4. The method of claim 2, wherein the tap density ratio is from 50-54.2%.

5. The method of claim 2, wherein the average particle size is from 10-25 microns.