Method for depositing a coating from an improved composition suspension

Patent metadata

Field	Value
Publication number	US-12173409-B2
Application number	US-202017772659-A
Country	US
Kind code	B2
Filing date	Oct 16, 2020
Priority date	Oct 28, 2019
Publication date	Dec 24, 2024
Grant date	Dec 24, 2024

Abstract

A process for the deposition of a coating on at least a part of a metallic substrate, a) mixing a liquid and a powder having particles of a metallic material to be deposited and particles of a pickling agent, so as to prepare a suspension, b) application of the suspension prepared in step a) to at least a part of the surfaces of the metallic substrate, so as to obtain a substrate-suspension assembly, c) carrying out a heat treatment of the assembly which includes heating at a first temperature of at least 500° C. and heating at a second temperature greater than the first temperature, and d) recovery of a substrate coated, at least in part, with a coating, the pickling agent being a halogenated compound and the suspension having from 10% to 60% of the pickling agent, with respect to the total weight of the powder.

First claim

The invention claimed is:

1. A process for the deposition of a coating on at least a part of a metallic substrate, said process comprising the following successive steps:
a) mixing a liquid and a powder comprising particles of a metallic material to be deposited and particles of a pickling agent, thereby preparing a suspension,
b) application of the suspension prepared in step a) to at least a part of the surfaces of the metallic substrate, thereby obtaining a substrate-suspension assembly,
c) carrying out a heat treatment of the substrate-suspension assembly which comprises heating at a first temperature of at least 500° C. and heating at a second temperature which is greater than the first temperature, and
d) recovery of a substrate coated, at least in part, with a coating,
said pickling agent being a halogenated compound and the suspension comprising from 10% to 60% by weight of said pickling agent, with respect to the total weight of the powder, wherein the particles of the metallic material exhibit a first mean equivalent diameter and the particles of the pickling agent exhibit a second mean equivalent diameter, the ratio of the first mean equivalent diameter to the second mean equivalent diameter being between 1.2 and 10.

2. The process as claimed in claim 1 , wherein the suspension comprises from 20% to 30% by weight of said pickling agent, with respect to the total weight of the powder.

3. The process as claimed in claim 1 , wherein the powder contains solely particles of the metallic material and particles of the pickling agent.

4. The process as claimed in claim 1 , wherein the particles of the metallic material exhibit a first mean equivalent diameter and the particles of the pickling agent exhibit a second mean equivalent diameter, the ratio of the first mean equivalent diameter to the second mean equivalent diameter being between 3.5 and 7.5.

5. The process as claimed in claim 4 , wherein the particles of the metallic material exhibit a first particle size distribution centered around the first mean equivalent diameter and the particles of the pickling agent exhibit a second particle size distribution centered around the second mean equivalent diameter, said first particle size distribution and/or said second particle size distribution exhibiting a dispersion index of less than 1.2.

6. The process as claimed claim 1 , wherein the particles of the metallic material exhibit a first mean equivalent diameter of between 7 and 15 μm and/or the particles of the pickling agent exhibit a second mean equivalent diameter of between 2 and 6 μm.

7. The process as claimed in claim 1 , wherein the particles of the suspension exhibit a mean sphericity factor of at least 0.3.

8. The process as claimed in claim 1 , wherein the metallic substrate exhibits at least one cavity of equivalent diameter e mm <2 mm and/or a length/width ratio of greater than 150, the particles of the suspension each exhibiting an equivalent diameter of less than e mm /10.

9. The process as claimed in claim 1 , wherein the ratio by weight of the powder to the liquid is between 1.5 and 3.

10. The process as claimed in claim 1 , wherein the pickling agent is a halogenated compound, the halogen of which is fluorine or chlorine.

11. The process as claimed in claim 1 , wherein the pickling agent belongs to the system of fluorinated compounds, said pickling agent chosen from the group consisting of K x AlF y , NH 4 F, MgF 2 and CaF 2 , with x between 1 and 3.

12. The process as claimed in claim 1 , wherein the liquid comprises an alcohol.

13. The process as claimed in claim 1 , wherein the metallic material comprises aluminum or an aluminum alloy.

14. The process as claimed in claim 1 , wherein, in step c), heating is carried out at a first temperature of between 500° C. and 700° C. for 1 to 4 hours and heating is carried out at a second temperature of between 900° C. and 1100° C. for 1 to 3 hours.

15. The process as claimed in claim 1 , wherein stage c) is carried out under an inert or reducing atmosphere or under vacuum.

16. The process as claimed in claim 1 , further comprising, between steps c) and d), a step e) carrying out, under an oxidizing atmosphere, an additional heat treatment with heating at a third temperature of between 900° C. and 1100° C. for 1 to 5 hours.

17. The process as claimed in claim 1 , wherein the substrate to be coated is a metallic component exhibiting a surface roughness of at least 20 μm and/or surface defects of oxide or unfused type.

18. The process as claimed in claim 1 , wherein the substrate to be coated is a component resulting from an additive manufacturing process.

Assignees

• Air Liquide
• Centre Nat Rech Scient
• Univ De Lorraine

Inventors

• Doublet Sébastien
• Ramenatte Nicolas
• Mathieu Stéphane
• Vilasi Michel
• Portebois Léo

Classifications

• Y02P10/25

  Process efficiency · CPC title

• C23C10/60

  After-treatment · CPC title

• C23C10/20

  only one element being diffused · CPC title

• C23C24/087 Primary

  Coating with metal alloys or metal elements only · CPC title

• C23C24/08 Primary

  by application of heat or pressure and heat (C23C24/04 takes precedence) · CPC title