Surface hardening of substrates by a particle-containing cavitating waterjet

Patent metadata

Field	Value
Publication number	US-11414717-B2
Application number	US-201816495536-A
Country	US
Kind code	B2
Filing date	Mar 21, 2018
Priority date	Mar 23, 2017
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

In an embodiment, a method of hardening a surface of a substrate comprises directing a waterjet having a transition flow region, the waterjet comprising water and particles, at a surface of a substrate such that the waterjet impacts the surface within the transition flow region to provide a layer of embedded particles underneath the surface of the substrate, thereby forming a hardened substrate. The hardened substrates are also provided.

First claim

What is claimed is:

1. A method of hardening a surface of a substrate, the method comprising directing a waterjet having a transition flow region, the waterjet comprising water and particles, at a surface of a substrate such that the waterjet impacts the surface within the transition flow region to provide a sub-surface layer of embedded particles underneath the surface of the substrate, thereby forming a hardened substrate.

2. The method of claim 1 , wherein the particles are nanoparticles, microparticles, or combinations thereof.

3. The method of claim 1 , wherein the particles are composed of a metal, a metal alloy, a metal oxide, a metal boride, a metal nitride, a metal carbide, a metal phosphide, a metal sulfide, a metal arsenide, a metal selenide, or combinations of such particles.

4. The method of claim 1 , wherein the surface of the substrate is composed of a metal or a metal alloy.

5. The method of claim 1 , wherein the substrate is composed of a metal or a metal alloy and the particles are transition metal oxide nanoparticles.

6. The method of claim 5 , wherein the substrate is an aluminum alloy and the particles are Y 2 O 3 nanoparticles.

7. The method of claim 1 , wherein the method is carried out at a temperature equal to or less than 100° C.

8. The method of claim 1 , wherein the hardened substrate is characterized by a depth of incorporation of the embedded particles and a hardening depth, wherein the hardening depth is at least about 5 times greater than the depth of incorporation.

9. The method of claim 1 , wherein the hardened substrate is characterized by a surface hardness which is at least about 5 times greater than a surface hardness of the substrate as measured prior to hardening.

10. The method of claim 9 , wherein the hardened substrate is characterized by a surface roughness R a value that is no more than about 2 times greater than that of the substrate as measured prior to hardening.

11. The method of claim 1 , wherein the hardened substrate further comprises a surface-strained layer extending from the surface of the substrate and over the sub-surface layer of embedded particles, wherein the sub-surface layer of embedded particles has a greater density of the particles than the surface-strained layer.

12. The method of claim 11 , further comprising a grain-refined layer under the sub-surface layer of embedded particles and an extended strained layer under the grain-refined layer.

13. A hardened substrate having a surface and comprising a sub-surface layer of embedded particles underneath the surface of the substrate.

14. The hardened substrate of claim 13 , wherein the substrate is composed of a metal or a metal alloy and the particles are composed of a transition metal oxide.

15. The hardened substrate of claim 14 , wherein the particles are nanoparticles.

16. The hardened substrate of claim 14 , wherein the substrate is an aluminum alloy and the particles are Y 2 O 3 nanoparticles.

17. The hardened substrate of claim 13 , wherein the hardened substrate is characterized by a surface hardness which is at least about 5 times greater than a surface hardness of the substrate absent the sub-surface layer of embedded particles.

18. The hardened substrate of claim 13 , wherein the hardened substrate is characterized by a surface roughness R a value that is no more than about 2 times greater than that of the substrate absent the sub-surface layer of embedded particles.

19. The hardened substrate of claim 13 , further comprising a surface-strained layer extending from the surface of the substrate and over the sub-surface layer of embedded particles, wherein the sub-surface layer of embedded particles has a greater density of the particles than the surface-strained layer.

20. The hardened substrate of claim 19 , further comprising a grain-refined layer under the sub-surface layer of embedded particles and an extended strained layer under the grain-refined layer.

Assignees

• Univ Northwestern

Inventors

• Wang Qian
• Chung Yip-Wah
• Ehmann Kornel F
• He Xingliang
• Shi Yi
• Liu Zhong

Classifications

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• B05B1/02

  designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, {or having an outlet of particular shape}(B05B1/26, B05B1/28, B05B1/34 take precedence) · CPC title

• C23C8/00

  Solid state diffusion of only non-metal elements into metallic material surfaces (diffusion of silicon C23C10/00); Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals (C23C14/00 takes precedence) · CPC title

• C21D1/06 Primary

  Surface hardening · CPC title

• B24C5/00

  Devices or accessories for generating abrasive blasts · CPC title