Method for the surface treatment of particles of a metal powder and metal powder particles obtained thereby

Patent metadata

Field	Value
Publication number	US-2020215607-A1
Application number	US-201816628355-A
Country	US
Kind code	A1
Filing date	Jun 21, 2018
Priority date	Jul 7, 2017
Publication date	Jul 9, 2020
Grant date	—

Abstract

A method for surface treatment of a metal material in a powder state is provided, the method including obtaining a powder formed from a plurality of particles of the metal material to be treated; and subjecting the powder to an ion implantation process by directing a beam of singly-charged or multi-charged ions towards an outer surface of the particles, the beam being produced by a source of singly-charged or multi-charged ions, whereby the particles have an overall spherical shape with a radius (R). There is also provided a material in a powder state formed from a plurality of particles having a ceramic outer layer and a metal core, the particles having an overall spherical shape.

First claim

1 .- 15 . (canceled)

16 . A method for surface treatment of a metal material in a powder state, the method comprising:
obtaining a powder formed from a plurality of particles of the metal material to be treated; and subjecting the powder formed from the plurality of particles of the metal material to an ion implantation process by directing a beam of singly-charged or multi-charged ions towards an outer surface of the particles, the beam being produced by a source of singly-charged or multi-charged ions, whereby the particles have an overall spherical shape with a radius (R).

17 . The method according to claim 16 , wherein the particles are agitated throughout a duration of the ion implantation process.

18 . The method according to claim 16 , wherein a grain size of the particles used is such that substantially 50% of all of the particles have a diameter that lies in a range of 1 micrometre to 2 micrometres, whereby the diameter of the particles does not exceed 50 micrometres.

19 . The method according to claim 16 , wherein the metal material is a precious metal selected from a group comprising gold and platinum.

20 . The method according to claim 16 , wherein the metal material is a nonprecious metal selected from a group comprising magnesium, titanium, and aluminium.

21 . The method according to claim 16 , wherein the metal material is chosen from a group comprising carbon, nitrogen, oxygen, and argon.

22 . The method according to claim 21 , wherein the ion implantation process is of an electron cyclotron resonance (ECR) type.

23 . The method according to claim 22 , wherein the singly-charged or multi-charged ions are accelerated under a voltage in a range 15,000 volts to 35,000 volts.

24 . The method according to claim 23 , wherein a dose of ions implanted lies in a range from 1·10 15 ions·cm −2 to 1·10 17 ions·cm −2 .

25 . The method according to claim 23 , wherein the singly-charged or multi-charged ions penetrate the particles up to a depth corresponding to about 10% of the radius (R) of the particles.

26 . A material in a powder state formed from a plurality of particles having a ceramic outer layer and a metal core, the particles having an overall spherical shape with a radius (R), the ceramic outer layer corresponding to a carbide or a nitride of a metal of which the metal core of the particles is made, a concentration of ceramic material increasing from an outer surface to a given depth beyond which the concentration of the ceramic material decreases and becomes zero.

27 . The material according to claim 26 , wherein the carbide or the nitride is a combination of carbon ions or nitrogen ions with atoms of the metal.

28 . The material according to claim 26 , wherein about 50% of the particles have a diameter that lies in a range of 1 micrometre to 2 micrometres, whereby the diameter of the particles does not exceed 50 micrometres.

29 . The material according to claim 26 , wherein the metal material is a precious metal selected from a group comprising gold and platinum.

30 . The material according to claim 26 , wherein the metal material is a nonprecious metal selected from a group comprising magnesium, titanium, and aluminium.

31 . The material according to claim 26 , wherein the concentration of the ceramic material increases from the outer surface to about 5% of a length of the radius (R) of the particles, then decreases to about 10% of the length of the radius (R) of the particles, where it is substantially zero.

Assignees

• Swatch Group Res & Dev Ltd

Inventors

• Miko Csilla
• Bazin Jean-Luc

Classifications

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title

• Y10T428/2993

  Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.] · CPC title

• Y10T428/2991

  Coated · CPC title

• Y10T428/2982

  Particulate matter [e.g., sphere, flake, etc.] · CPC title

• Y10T428/2495

  Thickness [relative or absolute] · CPC title