Method for passive metal activation and uses thereof

Patent metadata

Field	Value
Publication number	US-2020235374-A1
Application number	US-202016841821-A
Country	US
Kind code	A1
Filing date	Apr 7, 2020
Priority date	Mar 31, 2014
Publication date	Jul 23, 2020
Grant date	—

Abstract

Disclosed is a method for activating a surface of metals, such as self-passivated metals, and of metal-oxide dissolution, effected using a fluoroanion-containing composition. Also disclosed is an electrochemical cell utilizing an aluminum-containing anode material and a fluoroanion-containing electrolyte, characterized by high efficiency, low corrosion, and optionally mechanical or electrochemical rechargeability. Also disclosed is a process for fusing (welding, soldering etc.) a self-passivated metal at relatively low temperature and ambient atmosphere, and a method for electrodepositing a metal on a self-passivated metal using metal-oxide source.

First claim

What is claimed is:

1 . A method of welding a first metal object to a second metal object, wherein at least one of said first metal object or said second metal object comprises a self-passivated metal, the method comprising:
contacting a surface of said first metal object and/or said second metal object which comprises said self-passivating metal with a fluoroanion-containing composition that comprises a at least one [(HF)nF] − species, to thereby obtain an activated metal surface; melting at least one of the first metal object and/or the second metal object at said surface, and/or optionally melting a filler metal so as to fill an interface between the first metal object and the second metal object; and cooling the first metal object and the second metal object or cooling said filler, to thereby fuse the first metal object to the second metal object.

2 . The method of claim 1 , further comprising contacting a surface of said first metal object or said second metal object which do not comprises said self-passivated metal with a fluoroanion-containing composition that comprises a at least one [(HF)nF] − species, to thereby obtain an activated metal surface.

3 . The method of claim 1 , comprising melting said filler metal, the method further comprising contacting a surface of said filler metal with a fluoroanion-containing composition that comprises a at least one [(HF)nF] − species, to thereby obtain an activated metal surface.

4 . The method of claim 1 , wherein said filler metal is a self-passivated metal.

5 . The method of claim 1 , wherein said activated metal surface is essentially devoid of a passivation layer.

6 . The method of claim 5 , effected at a temperature lower than a melting temperature of said passivation layer.

7 . The method of claim 1 , wherein said activated metal surface comprises fluorohydrogenate-metal species (HF-species).

8 . The method of claim 1 , wherein said activated metal surface exhibits at least two peaks in an attenuated total reflection infrared spectrum having a wavenumber range selected from the group consisting of from 3150 cm 1 to 2840 cm 1, from 1110 cm 1 to 800 cm 1, from 2505 cm 1 to 2200 cm 1, from 1920 cm 1 to 1600 cm 1 and/or from 1170 cm 1 to 870 cm 1.

9 . The method of claim 1 , wherein said self-passivated metal is aluminum.

10 . The method of claim 1 , wherein said first metal alloy or said second metal alloy is an alloy steel.

11 . The method of claim 1 , wherein said fluoroanion-containing composition comprises a room temperature ionic liquid (a fluoroanion-RTIL).

12 . The method of claim 11 , wherein said RTIL is EMIm(HF)2.3F and/or Pyr14(HF)2.3F.

13 . A method for electrodepositing a first metal on a surface of a second metal, the method comprising contacting the second metal with a fluoroanion-containing composition that comprises a at least one [(HF)nF] − species to thereby afford an activated metal surface, and depositing the first metal on said activated surface.

14 . The method of claim 13 , further comprising:
separating the second metal from said fluoroanion-containing composition, placing the second metal in an electrolyte that comprises a source of said first metal, applying a cathodic potential or a cathodic current between the second metal while in said electrolyte and an electrode which is in an electrical communication with said electrolyte, to thereby effect electrodepositing.

15 . The method of claim 13 , further comprising adding a source of said first metal into said fluoroanion-containing composition.

16 . The method of claim 15 , further comprising applying a cathodic potential or a cathodic current between the second metal while in contact with said fluoroanion-containing composition, and an electrode which is in an electrical communication with said fluoroanion-containing composition to thereby effect electrodepositing.

17 . The method of claim 13 , the second metal is a self-passivated metal.

18 . The method of claim 13 , the first metal is copper and the second metal comprises tantalum.

19 . The method of claim 13 , effected without seeding the second metal with the first metal.

20 . The method of claim 13 , wherein said fluoroanion-containing composition comprises a room temperature ionic liquid (a fluoroanion-RTIL).

21 . The method of claim 20 , wherein said RTIL is EMIm(HF)2.3F and/or Pyr14(HF)2.3F.

Assignees

• Technion Res & Dev Foundation

Inventors

• Ein-Eli Yair
• Gelman Danny
• Shvartsev Boris
• Kraytsberg Alexander

Classifications

• C25D5/54

  Electroplating of non-metallic surfaces (C25D7/12 takes precedence) · CPC title

• C25D5/56

  of plastics · CPC title

• C25D5/38

  of refractory metals or nickel · CPC title

• B23K2103/10

  Aluminium or alloys thereof · CPC title

• B23K9/23

  taking account of the properties of the materials to be welded · CPC title