Electrochemical metal and alloy detector and method

Patent metadata

Field	Value
Publication number	US-2016178563-A1
Application number	US-201414576309-A
Country	US
Kind code	A1
Filing date	Dec 19, 2014
Priority date	Dec 19, 2014
Publication date	Jun 23, 2016
Grant date	—

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:
at least one electrically conductive probe; at least one electrically non-conductive component carrying an electrolyte and being in operative connection with the at least one electrically conductive probe; a separate electrical connection to each at least one electrically conductive probe; an electrical connection to the metallic sample, wherein the at least one electrically conductive probe is positioned against the metallic sample with the at least one electrically non-conductive component located in between, establishing an ionic path between each of at least one electrically conductive probe and the metallic sample; an electrical excitation device to provide to each at least one electrically conductive probe and the metallic sample, asymmetric excitations; an electrical measurement device to measure at least one of voltages and currents between the 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 measured currents and voltages with respective metal and/or alloy compositions of the metallic sample.

2 . The probe system of claim 1 , wherein the electrically conductive probe is 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 electrically conductive probe is made out of a metal that forms a galvanic coupling through the electrolyte with the metallic sample.

4 . The probe system of claim 1 , wherein the electrically conductive probe is made out of a metal salt or metal salt composite that forms a galvanic coupling through the electrolyte with the metallic sample.

5 . The probe system of claim 1 , wherein the electrically non-conductive component is a membrane composed of a porous or fibrous polymeric material with open pores, and wherein the membrane is 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 the electrically non-conductive component is a non-porous ion exchange membrane.

7 . The probe system of claim 1 , wherein the electrolyte is 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 electrolyte medium.

9 . The electrolyte of claim 7 , wherein metal redox cations are one of Fe2+/Fe3+, Ce3+/Ce4+, V2+N3+, V3+N4+, V4+N5+, Cu+/Cu2+, Sn2+/Sn4+, Ni2+/Ni3+.

10 . The probe system of claim 1 , further including a cleaning configuration to clean a surface of the metallic sample prior to the electrically non-conductive component and the probe making contact with the metallic sample, the cleaning configuration 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 11 , wherein the alternating current is asymmetric in magnitude.

13 . The probe system of claim 11 , wherein the electronic excitation device which generates the asymmetric alternating current is programmed such that the net electronic charge transferred between the probe and the sample is zero.

14 . 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.

15 . 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.

16 . 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.

17 . The probe system of claim 1 further including,
a second electrically conductive probe;
a second electrically non-conductive component carrying a second electrolyte different from the electrolyte carried by the at least one electrically non-conductive component,
wherein the second electrically conductive probe and the second electrically non-conductive component carrying the second electrolyte is positioned against the metallic sample to obtain additional measurements of the metallic sample to assist in obtaining additional correlations by the electronic computing device.

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

19 . An electrochemical probe system for identification of a metallic sample comprising:
an electrically conductive probe; an electrically non-conductive component in operative association with the electrically conductive probe; an electrolyte carried by the electrically non-conductive component; an electrical connection to the electrically conductive probe; an electrical connection to the metallic sample; wherein, an ionic path is formed with the electrically conductive probe positioned against the metallic sample with the electrically non-conductive component located there between; an electrical excitation device configured to provide asymmetric current pulses to the electrically conductive probe and the metallic sample; an electrical measurement device to measure voltage potentials between the electrically conductive probe and the metallic sample; and an electronic computing device configured to store voltages representing various metals and/or metal alloys, to receive the measured voltages from the electronic measurement device and to correlate the measured voltages with the stored voltages to identify respective metal and/or metal alloy compositions of the metallic samples.

Assignees

• Palo Alto Res Ct Inc

Inventors

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

Classifications

• G01N27/38

  Cleaning of electrodes · CPC title

• G01N27/308

  at least partially made of carbon · CPC title

• G01N27/333 Primary

  Ion-selective electrodes or membranes (glass electrodes G01N27/36) · CPC title

• G01N33/202

  Constituents thereof · CPC title

• G01N27/416 Primary

  Systems (G01N27/27 takes precedence) · CPC title