Water-leachable alloy-melt-swapping process and porous metal manufactured using the same

Patent metadata

Field	Value
Publication number	US-10538826-B2
Application number	US-201715685012-A
Country	US
Kind code	B2
Filing date	Aug 24, 2017
Priority date	Aug 26, 2016
Publication date	Jan 21, 2020
Grant date	Jan 21, 2020

Abstract

Disclosed is an AMS process using a water-leachable alloy that reacts with water and dissolves, and a porous metal manufactured using the same. An AMS precursor including element groups that are selected in consideration of the relationship of heat of mixing with the water-leachable alloy composition to be subjected to the AMS process is immersed in the alloy melt, thus manufacturing a bi-continuous structure alloy. The bi-continuous structure alloy is subjected to dealloying using water, thus manufacturing the porous metal. The water-leachable alloy is a Ca-based alloy having high reactivity to water and high oxidation resistance at high temperatures, and a dealloying process thereof is performed using only pure water, unlike a conventional dealloying process performed using a toxic etching solution of a strong acid/strong base. The metal porous body has high elongation, a large surface area, and low thermal conductivity.

First claim

What is claimed is:

1. A method of manufacturing a porous metal using a water-leachable alloy-melt-swapping process (AMS), the method comprising:
preparing a water-leachable alloy having excellent oxidation resistance;
preparing an AMS precursor including a composition having a relationship of both positive (+) and negative (−) heats of mixing with the water-leachable alloy elements;
manufacturing a bi-continuous structure alloy by immersing the AMS precursor in a water-leachable alloy melt prepared by melting the water-leachable alloy; and
manufacturing the porous metal using dealloying, performed by immersing the bi-continuous structure alloy in pure water.

2. The method of claim 1 , wherein preparing the water-leachable alloy having the excellent oxidation resistance is performed using a Ca-based alloy.

3. The method of claim 2 , wherein the Ca-based alloy is represented by Ca x Mg 100-x wherein 55≤x≤82 at. %.

4. The method of claim 1 , wherein preparing the AMS precursor includes manufacturing an AMS precursor having a composition including one or more elements selected from an element group II wherein element group II includes Ti, V, Cr, Mn, Fe, Co, Zr, Nb, Mo, Hf, Ta, W, and Re, which have the positive (+) heat of mixing, with element group I which comprises Ca and Mg and which are main elements of the water-leachable alloy, and one or more elements selected from an element group III wherein element group III includes Al, Si, P, Ni, Cu, Zn, Ga, Ge, As, Pd, Ag, Cd, In, Sn, Sb, Pt, Au, Hg, Tl, Pb, and Bi, which have the negative (−) heat of mixing with the element group I comprising Ca and Mg.

5. The method of claim 4 , wherein the composition of the elements selected from the element group II and the elements selected from the element group III is (element group II) 100-y (element group III) y wherein 5≤y≤95 at. %.

6. The method of claim 1 , wherein manufacturing the bi-continuous structure alloy includes immersing the AMS precursor, which is obtained by alloying one or more elements selected from an element group II wherein element group II includes Ti, V, Cr, Mn, Fe, Co, Zr, Nb, Mo, Hf, Ta, W, and Re and one or more elements selected from an element group III, wherein element group III includes Al, Si, P, Ni, Cu, Zn, Ga, Ge, As, Pd, Ag, Cd, In, Sn, Sb, Pt, Au, Hg, Tl, Pb, and Bi in the alloy melt including an element group I which comprises Ca and Mg, so as to perform selective swapping of constituent elements, thus forming the bi-continuous structure alloy including the element group I and the element group II.

7. The method of claim 6 , wherein manufacturing the bi-continuous structure alloy includes controlling a microstructure of the bi-continuous structure alloy by changing an immersion time of the AMS precursor in the alloy melt.

8. The method of claim 6 , wherein manufacturing the bi-continuous structure alloy includes additionally introducing a process for increasing a rate of a diffusion reaction in the melt, which is selected from among mechanical stirring method, agitation using an electromagnetic field, and vibration of the melt using ultrasonic waves, thus changing a diffusion rate so as to control a microstructure of the bi-continuous structure alloy.

9. The method of claim 1 , wherein manufacturing the porous metal via the dealloying using the water includes manufacturing a porous body including an element selected from element group II wherein element group II includes Ti, V, Cr, Mn, Fe, Co, Zr, Nb, Mo, Hf, Ta, W, and Re by dissolving the bi-continuous structure alloy composed of an element group I comprising Ca and Mg and the element group II in the water to thus perform the dealloying of the element group I.

10. The method of claim 9 , wherein an internal porosity of the porous metal is controlled by adjusting y in a composition of the AMS precursor represented by (element group II) 100-y (element group III) y wherein 5≤y≤95 at. %.

11. The method of claim 9 , wherein an internal porosity of the porous metal is controlled by adjusting a time of the dealloying using the water.

Assignees

• Seoul Nat Univ R&Db Foundation

Inventors

• Park Eunsoo
• Yoon Kooknoh
• Lee Jein
• RYU Wookha
• Yoo Geun Hee

Classifications

• C23F4/04

  by physical dissolution · CPC title

• C22B9/22 Primary

  with heating by wave energy or particle radiation {(by acoustic waves C22B9/026)} · CPC title

• Y10T428/12479

  Porous [e.g., foamed, spongy, cracked, etc.] · CPC title

• C22C1/02

  by melting {(C22C1/1036 takes precedence)} · CPC title

• C23C26/02

  applying molten material to the substrate · CPC title