Electrochemical metal and alloy detector and method

Patent metadata

Field	Value
Publication number	US-9880144-B2
Application number	US-201414576309-A
Country	US
Kind code	B2
Filing date	Dec 19, 2014
Priority date	Dec 19, 2014
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

Disclosed is an electrochemical probe system and an electrical excitation method, used to identify the composition of metals and alloys.

First claim

What is claimed is:

1. An electrochemical probe system for identification of a metallic sample, comprising:
a first electrically conductive probe;
a first electrically non-conductive component carrying a first electrolyte and being in operative connection with the first electrically conductive probe;
a second electrically conductive probe;
a second electrically non-conductive component carrying a second electrolyte different from the first electrolyte, and being in operative connection with the second electrically conductive probe;
a separate electrical connection to at least one of the first electrically conductive probe and the second electrically conductive probe;
an electrical connection to the metallic sample, wherein the first electrically conductive probe is positioned against the metallic sample with the first electrically non-conductive component located in between, establishing an ionic path between the first electrically conductive probe and the metallic sample;
another electrical connection to the metallic sample, wherein the second electrically conductive probe is positioned against the metallic sample with the second electrically non-conductive component located in between, establishing an ionic path between the second electrically conductive probe and the metallic sample;
an electrical excitation device to provide to the first electrically conductive probe, the second electrically conductive probe and the metallic sample, asymmetric excitations;
an electrical measurement device to measure at least one of voltages and currents between the first electrically conductive probe and the metallic sample, and between the second electrically conductive probe and the metallic sample; and
an electronic computing device configured to operate an algorithm and/or store a look-up table that correlates the at least one of measured currents and voltages with respective metal and/or alloy compositions of the metallic sample, the metallic sample including one or more pieces of metal and/or metal alloy, wherein the second electrically conductive probe and the second electrically non-conductive component carrying the second electrolyte assist in obtaining additional correlations in addition to those correlations associated with the first electrically conductive probe and the first electrically non-conductive component carrying the first electrolyte.

2. The probe system of claim 1 , wherein the first and second electrically conductive probes are each made out of at least one of glassy carbon, graphite, carbon-plastic composite, and other forms of carbon.

3. The probe system of claim 1 , wherein the first and second electrically conductive probes are made out of a metal that forms a galvanic coupling through the first and second electrolytes with the metallic sample.

4. The probe system of claim 1 , wherein the first and second electrically conductive probes are each made out of a metal salt or metal salt composite that forms a galvanic coupling through the first and second electrolytes with the metallic sample.

5. The probe system of claim 1 , wherein each of the first and second electrically non-conductive components are configured as membranes composed of a porous or fibrous polymeric material with open pores, and wherein the membranes are in at least one of a planar format and shaped as a sleeve that covers the probe, and wherein the membrane is configured to be re-used for multiple measurements, or discarded after each measurement.

6. The probe system of claim 1 , wherein each of the first and second electrically non-conductive components include a non-porous ion exchange membrane.

7. The probe system of claim 1 , wherein the first and second electrolytes are capable of exchanging a reversible redox reaction with the metals present in the metallic sample being probed.

8. The electrolyte of claim 7 , wherein a cation consists of a metal ion having at least two redox states that are soluble in the first and second electrolyte medium.

9. The electrolyte of claim 7 , wherein metal redox cations are one of Fe2+/Fe3+, Ce3+/Ce4+, V2+/V3+, V3+/V4+, V4+/V5+, Cu+/Cu2+, Sn2+/Sn4+, Ni2+/Ni3+.

10. The probe system of claim 1 , further including a cleaning arrangement to clean a surface of the metallic sample, the cleaning arrangement including at least one of an abrasive cleaning arrangement, a chemical cleaning arrangement, a milling based cleaning arrangement, a chemical etching cleaning arrangement, and a mechanical puncture based cleaning arrangement.

11. The probe system of claim 1 , wherein the excitations of the electrical excitation device includes alternating current with a current density having any value between and including approximately 0.1 uA/cm2 to 10 mA/cm2.

12. The probe system of claim 1 , wherein a net electrical excitation to the metallic sample is null, and the measurement taken is a voltage measurement.

13. The probe system of claim 1 , wherein the electrical excitation to the metallic sample is an applied and positive constant current of between, approximately 0.1 uA/cm2 and 10 mA/cm2.

14. The probe system of claim 1 , wherein the electrical excitation to the metallic sample is an applied and negative constant current of between, approximately −0.1 uA/cm2 and −10 mA/cm2.

15. A method for electrochemically identifying a metallic sample, comprising:
establishing a first ionic path between a first electrically conductive probe and a metallic sample by placement of a first electrically non-conductive membrane carrying a first electrolyte, between and in operative contact with the first electrically conductive probe and the metallic sample;
establishing a second ionic path between a second electrically conductive probe and a metallic sample by placement of a second electrically non-conductive membrane carrying an electrolyte, between and in operative contact with the second electrically conductive probe and the metallic sample;
generating and providing asymmetric excitations to the electrically conductive probe and the metallic sample;
measuring at least one of voltages and currents between the first and second probes and the metallic sample, by use of an electronic measuring device; and
correlating the measured voltages and currents of the first and second probes with voltages and currents corresponding to respective metal and/or metal alloy compositions to identify the metallic sample as including a specific metal and/or metal alloy, the metallic sample including one or more pieces of metal and/or metal alloy.

16. An electrochemical probe system for identification of a metallic sample comprising:
a first electrically conductive probe;
a first electrically non-conductive component in operative association with the first electrically conductive probe;
a second electrically conductive probe;
a second electrically non-conductive component in operative association with the second electrically conductive probe;
an electrolyte carried by the first and second electrically non-conductive component;
a separate electrical connection to each of the first electrically conductive probe and the second electrically conductive probe;
an electrical connection to the metallic sample including the first electrically conductive probe, and the first electrically non-conductive component;
another electrical connection to the metallic sample including the first electrically conductive probe, and the first electrically non-conductive component;
wherein, an ionic path is formed with the first and second electrically conductive probes positioned against the metallic sample with the respective electric

Assignees

• Palo Alto Res Ct Inc

Inventors

• Sahu Saroj
• Eldershaw Craig
• Vedharathinam Vedasri
• Desai Divyaraj
• Rivest Jessica Louis Baker
• Rao Ranjeet

Classifications

• G01N27/416 Primary

  Systems (G01N27/27 takes precedence) · CPC title

• G01N33/20 Primary

  Metals · CPC title

• G01N27/308

  at least partially made of carbon · CPC title

• G01N33/202

  Constituents thereof · CPC title