Method of coating metallic powder particles with silicon

Patent metadata

Field	Value
Publication number	US-10011900-B2
Application number	US-201615178297-A
Country	US
Kind code	B2
Filing date	Jun 9, 2016
Priority date	Jan 23, 2015
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

A method of coating metallic powder particles includes disposing an amount of metallic powder particles in a fluidizing reactor and removing moisture adhered to the powder particles within the reactor with a working gas at an elevated temperature for a predetermined time. The method further includes coating the powder particles in the reactor with silicon present within the precursor gas at an elevated temperature for a predetermined time and purging the precursor gas from the reactor using the working gas.

First claim

The invention claimed is:

1. A method of coating metallic powder particles with silicon comprising:
disposing an amount of metallic powder particles within a fluidizing reactor;
removing moisture adsorbed to the powder particles disposed within the reactor using a working gas at a temperature of from about 350° C. to about 450° C. for about 3 to 8 hours;
coating the powder particles disposed within the reactor with silicon present within a precursor gas at a temperature of from about 300° C. to about 500° C. for about 0.5 hours to about 7.5 hours; and
purging the precursor gas from the reactor using the working gas;
wherein the coating includes coating the powder particles with silicon in an amount such that the coated powder particles have an optical reflectivity that reflects less than 30% of incident light for subsequent processing of the coated powder particles within an additive manufacturing process.

2. The method of claim 1 , wherein the working gas comprises argon, nitrogen or He.

3. The method of claim 1 , wherein the metallic powder particles are aluminum alloy.

4. The method of claim 3 , wherein the aluminum alloy is selected from a group consisting of aluminum 5056, aluminum 6061, and aluminum 7075.

5. The method of claim 4 , wherein the aluminum alloy comprises aluminum 6061.

6. The method of claim 1 , wherein removing moisture adsorbed to the powder particles using a working gas at an elevated temperature for a predetermined time comprises heating in nitrogen to about 400° C. for about 4-8 hours.

7. The method of claim 1 , wherein the precursor gas is selected from the group consisting of silane (SiH 4 ), disilane (Si 2 H 6 ), chlorosilane (SiH 3 Cl), and dichlorosilane (SiH 2 Cl 2 ).

8. The method of claim 1 , wherein coating the powder particles, disposed within the reactor, with silicon within a precursor gas comprises exposing the particles to a 1% SiH 4 -H 2 gas mixture at a temperature of about 450° C. for about 0.5-3 hours.

9. A method of coating metallic powder particles with silicon, comprising:
providing a system having a fluidized reactor, a working gas source, a precursor gas source, and a processor adapted to execute instructions to control and monitor operation of the system, wherein the processor is in communication with a memory operable to store the executable instructions;
disposing an amount of metallic powder particles within the fluidizing reactor;
controlling the system to remove moisture adhered to the powder particles disposed within the reactor using a working gas provided from the working gas source at from about 350° C. to about 450° C. temperature for about 3 hours to about 8 hours;
controlling the system to coat the powder particles disposed within the reactor with silicon present in a precursor gas provided from the precursor gas source at a temperature of from about 300° C. to about 500° C. for about 0.5 hours to about 7.5 hours such that the coated powder particles have an optical reflectivity that reflects less than 30% of incident light for subsequent processing of the coated powder particles within an additive manufacturing process; and
controlling the system to purge the precursor gas from the reactor using the working gas.

10. The method of claim 9 , wherein the metallic powder particles are selected from a group consisting of aluminum 5056, aluminum 6061, and aluminum 7075.

11. The method of claim 10 , wherein the aluminum alloy comprises aluminum 6061.

12. The method of claim 9 , wherein removing moisture with the working gas, at a predetermined temperature for a predetermined time comprises nitrogen at about 400° C. for about 4-8 hours.

13. The method of claim 9 , wherein the precursor gas is selected from a group consisting of silane (SiH 4 ), disilane (Si 2 H 6 ), chlorosilane (SiH 3 Cl), and dichlorosilane (SiH 2 Cl 2 ).

14. The method of claim 11 , wherein coating the aluminum 6061 particles in the precursor gas at a predetermined temperature for a predetermined time comprises coating the particles in a 1% SiH 4 -H 2 gas mixture at a temperature of about 450° C. for about 0.5-3 hours.

15. A system for coating metallic powder particles to configure the metallic powder particles for use in an additive manufacturing process, the metallic powder particles being coated with silicon to reduce optical reflectivity of the coated metallic particles to 30% or less, the system comprising:
at least one working gas source;
at least one precursor gas source;
at least one fluidizing reactor, wherein the fluidizing reactor is in communication with the working gas source and the precursor gas source; and
a processor adapted to execute instructions to control operation of the system, wherein the executable instructions are operable to control the system to:
remove moisture adhered to the powder particles disposed within the reactor using a working gas provided from the working gas source at about 350° C. to about 450° C. for about 3 hours to about 8 hours;
coat the powder particles disposed within the reactor with a material present within a precursor gas provided from the precursor gas source at a temperature of from about 300° C. to about 500° C. for about 0.5 hours to about 7.5 hours to produce coated powder particles having an optical reflectivity that reflects 30% of incident light or less; and
purge the precursor gas from the reactor using the working gas.

16. The system of claim 15 , wherein the metallic powder particles are aluminum alloy 6061 particles.

17. The system of claim 15 , wherein the moisture is removed at about 400° C. for about 4-8 hours in a nitrogen working gas.

18. The system of claim 15 , wherein the metallic powder particles are coated with silicon in a 1% SiH 4 -H 2 gas mixture at a temperature of about 450° C. for about 0.5-3 hours.

Assignees

• United Technologies Corp

Inventors

• She Ying
• Beals James T

Classifications

• B22F1/16 Primary

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

• C23C16/24

  Deposition of silicon only · CPC title

• H04M3/385

  using speech signals · CPC title

• Y02P10/295

  Cross-Sectional Technologies · mapped topic

• H04M3/42221

  Conversation recording systems (at the subscriber's set H04M1/656) · CPC title