U.S. patent application number 14/904752 was filed with the patent office on 2016-06-16 for reduced conductivity and unique electro-magnetic signature zinc alloy.
This patent application is currently assigned to The United States Playing Card Company. The applicant listed for this patent is JARDEN ZINC PRODUCTS, LLC. Invention is credited to Randy Beets, Carl R. DelSorbo, William Lee Ketner, David Vernon Kyaw.
Application Number | 20160168664 14/904752 |
Document ID | / |
Family ID | 52587299 |
Filed Date | 2016-06-16 |
United States Patent
Application |
20160168664 |
Kind Code |
A1 |
DelSorbo; Carl R. ; et
al. |
June 16, 2016 |
Reduced Conductivity and Unique Electro-Magnetic Signature Zinc
Alloy
Abstract
An alloy, comprising up to 2% by weight of manganese and the
balance zinc broadens the use of low cost zinc in coinage and token
applications as well as in electrical and electronic applications.
Additions of small amounts of manganese can have a significant
effect on lowering the conductivity of zinc and its alloys.
Inventors: |
DelSorbo; Carl R.;
(Greeneville, TN) ; Beets; Randy; (Buuls Gap,
TN) ; Ketner; William Lee; (Jonesborough, TN)
; Kyaw; David Vernon; (Greeneville, TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
JARDEN ZINC PRODUCTS, LLC |
Greeneville |
TN |
US |
|
|
Assignee: |
The United States Playing Card
Company
Greeneville
TN
|
Family ID: |
52587299 |
Appl. No.: |
14/904752 |
Filed: |
August 27, 2014 |
PCT Filed: |
August 27, 2014 |
PCT NO: |
PCT/US14/52969 |
371 Date: |
January 13, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61870485 |
Aug 27, 2013 |
|
|
|
Current U.S.
Class: |
420/516 |
Current CPC
Class: |
C22C 38/00 20130101;
C22C 21/18 20130101; C22C 9/01 20130101; C22C 9/06 20130101; C22C
21/16 20130101; C22C 38/44 20130101; C22C 18/02 20130101; C22C
21/00 20130101; C22C 9/02 20130101; C22C 21/10 20130101; C22C 18/00
20130101; B32B 15/01 20130101 |
International
Class: |
C22C 21/18 20060101
C22C021/18; C22C 21/10 20060101 C22C021/10; C22C 21/00 20060101
C22C021/00; C22C 21/16 20060101 C22C021/16 |
Claims
1. An alloy, comprising: up to 2% by weight of manganese and the
balance zinc.
2. The alloy of claim 1, further comprising electrical conductivity
in the range of 12 to 25% IACS.
3. The alloy of claim 1, wherein said manganese comprises 0.01% to
2% by weight of said alloy.
4. The alloy of claim 1, further comprising copper in the range of
0.1% to 1.2% by weight.
5. The alloy of claim 1, further comprising titanium.
6. The alloy of claim 1, further comprising at least one of the
group consisting of copper, aluminum, magnesium, titanium, cadmium,
chromium, iron and antimony.
7. The alloy of claim 1, formed into a coin or token.
8. The alloy of claim 1, formed into a fuse.
9. The alloy of claim 1, having an as-cast IACS conductivity
modified by a rolling process.
10. The alloy of claim 1, further comprising a plating layer over
said alloy.
11. The alloy of claim 1, wherein said manganese comprises 0.05% to
1% of said alloy.
12. The alloy of claim 1, wherein said manganese comprises 0.01% to
1% of said alloy.
13. The alloy of claim 1, further comprising aluminum in the amount
of 0.001% to 0.60% by weight.
14. The alloy of claim 1, further comprising magnesium in the
amount of 0.0001% to 0.50% by weight.
15. The alloy of claim 1, further comprising titanium in the amount
of 0.050% to 1.0% by weight.
16. The alloy of claim 1, further comprising chromium in the amount
of 0.0001% to 0.50% by weight.
17. The alloy of claim 1, further comprising iron in the amount of
0.0001% to 0.50% by weight.
18. The alloy of claim 1, further comprising antimony in the amount
of 0.0001% to 0.50% by weight.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit and priority of U.S.
provisional patent application No. 61/870,485, filed on Aug. 27,
2013 and is incorporated herein by reference in its entirety.
BACKGROUND
[0002] Various metals are used in the coinage, electrical and
electronics markets with each metal having unique properties.
Rolled and die cast zinc products have been long standing product
offerings in these markets. The various base metal zinc alloys
currently on the market have measured electrical conductivity
values in the range of about 25% to 30% IACS based on the
International Annealed Copper Standard (IACS) which uses
substantially pure copper as a 100% conductivity reference (100%
IACS). These conventional zinc alloy electrical conductivity
values, although providing certain unique electrical properties,
have limited zinc alloys from broader use in coinage, electrical
and electronics markets.
[0003] In the coinage market, the electrical conductivity and
permeability of the metal provides a unique electromagnetic
signature that is used for security purposes. This electromagnetic
signature provides an additional source of security in coin
differentiation systems used in both the vending and banking
industries. The more common metals and alloys used in this
industry, such as low carbon steels, stainless steels, nickel,
copper, brasses, bronzes, cupronickel, aluminum bronze, and
aluminum, have electrical conductivities either at or below 15%
IACS or above 25% IACS.
[0004] There is a range from about 15% to 25% IACS in which a
cost-effective metal or alloy could provide a unique range of
electromagnetic signatures to provide additional security options
for new or redesigned coinage products. In addition, a more
cost-effective zinc metal or alloy option that can duplicate the
electromagnetic signature of an existing coinage product can
provide a more economical solution to the coinage market while
maintaining current coin differentiation parameters.
[0005] In the electrical and electronics market, the effective
range of electrical conductivity of a material, along with other
properties, can limit its use. By expanding this effective range,
the ease and/or cost of production can be improved for existing
uses and the range of applications for that material can also be
expanded. Currently, rolled zinc alloys have been used in the
automotive fuse market, as well as for shielding applications from
electromagnetic and radio frequency interference and counterpoise
grounding applications all utilizing the zinc alloys conventional
electrical conductivity property range. Expanding the current
effective electrical conductivity range for rolled zinc products
would allow for additional uses in these existing markets as well
as expand the use of zinc alloys for additional applications within
this industry.
SUMMARY
[0006] Coins should inherently be lower in cost than their stated
value to prevent destruction and manipulation of the coins for
monetary gain. Zinc base alloys provide a low cost base metal from
which to produce coinage which is less likely to be destroyed for
its inherent material value than more costly metals.
[0007] Coins can be identified as genuine by many methods including
coin design features, color, size, weight and shape, but are
increasingly identified by their unique electromagnetic properties.
This allows for quick and accurate authentication by machines.
These properties are inherent within the base metal or are an
artifact of a combination of the base metal and plated or coated
surfaces, base metal and clad materials, and/or inclusion in a
bi-metal coin system (two piece coin).
[0008] A range of new zinc alloys has been developed that has lower
electrical conductivity than conventional zinc alloys thereby
providing a wider and more unique range of electromagnetic
properties. This broadens current security options in coins.
[0009] A further advantage of this new range of conductivity of
zinc alloys is a series of alloys with controllable conductivity
for applications in electrical and electronic markets. The alloy
may be produced as a rolled product or in a traditional die casting
process for various applications.
[0010] As noted above, current rolled zinc strip alloys and die
cast zinc materials have a limited conductivity range of about 25%
to 30% IACS. This limits their use in both the coinage, electrical
and electronics markets. The alloys described herein expand the
effective conductivity range and electromagnetic signature of
rolled and die cast zinc products allowing for expansion of use in
current markets and application into new markets.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the drawings:
[0012] FIG. 1 is a graph depicting the effect on electrical
conductivity of a zinc based alloy by the addition of manganese to
zinc;
[0013] FIG. 2 is a graph similar to FIG. 1 depicting the expanded
effect on electrical conductivity of a zinc based alloy by the
addition of manganese and additional alloying agents;
[0014] FIG. 3 is a series of plots derived from a coin sorting
machine depicting the electromagnetic signatures of two
zinc-manganese alloys formulated as described herein and compared
with five other common coinage materials; and
[0015] FIG. 4 is a schematic perspective view of a blade fuse
having a fuse wire constructed with a zinc-manganese alloy.
DETAILED DESCRIPTION
[0016] A range of new zinc based alloys has been produced which
contain manganese in the weight range of 0.01 to 2.0 percent for
reducing the electrical conductivity of zinc. These alloys show
unique properties, most notably, an electrical conductivity lower
than typical zinc and zinc alloys produced as strip. The initial
alloys tested were simple binary compositions of zinc and manganese
and later, alloys containing other elements were tested. That is,
alloys of zinc and manganese in the weight range noted above were
combined with stabilizing agents, such as copper in the amount of
0.1% to 1.2% by weight, aluminum in the amount of 0.001% to 0.60%
by weight, titanium in the amount of 0.050% to 1.0% by weight,
magnesium in the amount of 0.0001% to 0.050% by weight, cadmium in
the amount 0.0001% to 0.50% by weight, chromium in the amount of
0.0001% to 0.50% by weight, iron in the amount of 0.0001% to 0.50%
by weight and antimony in the amount of 0.0001% to 0.50% by weight.
Stabilization refers to the ability of the zinc manganese alloy to
maintain a substantially constant IACS conductivity over time and
over varying temperature conditions. Any variation is referred to
as "drift."
[0017] For example, copper in the amount of about 0.1% to 1.2% by
weight can be added as a hardener to a zinc manganese alloy of
0.05% to 2% by weight manganese, balance zinc. Titanium, magnesium,
cadmium and chromium serve as grain refiners to produce smaller
grains in the zinc manganese alloy and form intermetallic compounds
which resist conductivity drift.
[0018] Titanium not only serves as a grain refiner in the zinc
manganese alloy, it also lowers the IACS conductivity of the zinc
alloy in its as cast state. Moreover, by adding titanium to the
alloy, conductivity drift is reduced at any given level of
manganese. A useful weight range of titanium is 0.05% to 1% by
weight of the alloy.
[0019] Testing has shown that the IACS test results places the
conductivity of these new alloys in the range of 12% to 25% of
IACS. Again, zinc alloys generally lie in the range of 25% to 30%
of IACS. The conductivity of the alloys can be controlled with
secondary effects based on rolling, heat treating and plating
practice yielding processes for creating a range of electronic
signatures within the zinc and manganese alloy system. This range
of conductivity is unique compared to general commercial alloys of
common metals.
[0020] The ability to significantly adjust the conductivity of a
zinc based alloy with small amounts of manganese has many potential
applications. This unique conductivity space of the alloy initially
provides two potential applications. The first is in the production
of coinage with a unique electromagnetic signature (EMS). Coins for
purposes of sorting or vending are often identified within a
machine by a variety of criterion. The first is the physical
parameters such as size and weight that are clearly evident and
generally easy to copy. But the electro-magnetic signature of a
coin consisting of a base metal that may or may not have one or
more plated layers, can be unique.
[0021] As described further below, the second application for this
new range of low conductivity alloys is within the electronics and
fuse market, where the protective value of the fuse (amperage at
the point of planned failure) is controlled by conductivity and
geometry. Typically, a fuse is designed from a particular alloy and
then the geometry is changed to control the final fuse value. In
some cases, it is desirable to make a fuse for low amperage
control, but which is complicated by the ability to reliably
produce small geometric cross-sections. An alloy of 50% lower
conductivity would allow more manufacturability within the fuse
industry.
[0022] The key to this controlled conductivity is dominated by the
quantity of manganese in the zinc, but the full range of potential
alloys possible may need exploration to best control the space.
Alloys with 0 to 2% by weight of manganese balance zinc, and
preferably 0 to 1% by weight of manganese balance zinc have been
found to produce conductivity in ranges not previously achievable.
The addition of copper to the zinc-manganese alloys acts as a
hardener in the range of 0.1 to 1.2 weight percent. This addition
increases the hardness without adverse affects on adjustment of
conductivity by the manganese content in the zinc. Elements that
fall in this grouping of increasing hardness and/or strength of
zinc-manganese alloys include copper, titanium, magnesium,
aluminum, chromium, iron, antimony and/or cadmium. These elements
also act as stabilizing agents to prevent IACS drift.
[0023] A cast alloy of zinc and manganese exhibits a certain
initial conductivity. When rolled into a coil, the conductivity
increases by about 3% to 4% on the IACS scale. By adjusting the
rolling process to roll at a lower metal temperature, the increase
in conductivity can be minimized to about 1% to 2% IACS. Lower
annealing temperature can also have an effect on lowering the
conductivity of rolled alloys.
[0024] As shown in FIG. 1, the binary alloy of zinc and manganese
in the range of 0.0 to 1.0% manganese produces a vast range of
conductivities. The addition of manganese trends to lower
conductivity. However, with variation in processing conditions,
such as rolling and plating practice, a range of conductivities can
be produced at varying manganese levels. The lower boundary of the
plot in FIG. 1 represents the as cast alloy conductivity while the
upper boundary of the plot represents the alloy conductivity after
an aging process at about 220.degree. F. producing a drift of about
5% IACS. Noticeable effects on the conductivity of zinc can be seen
beginning around 0.01% by weight manganese and clearly at 0.05% by
weight manganese. These alloys contain from about 0.01% up to 2%
manganese, balance zinc, and more preferably 0.05% manganese up to
2% manganese balance zinc. More desirable effects on conductivity
can be achieved with 0.05% to 1.0% by weight manganese, balance
zinc. Of course, additional stabilizing agents such as those noted
above can be added to any of these zinc-manganese alloys.
[0025] As noted above, the electrical conductivity of a
zinc-manganese alloy can be further modified with the introduction
of stabilizing agents into the binary zinc-manganese alloys. As
observed in FIG. 2, a larger range of conductivities can be
produced with the addition of, for example, two of the stabilizing
agents noted above, thereby forming a quaternary alloy with zinc
and manganese. In this example, copper and titanium were added in
the ranges noted herein to the zinc-manganese alloy as described
herein. Further expansion of the potential conductivity ranges can
be achieved with varying the alloy processing conditions. The lower
boundary curve again represents the conductivity of the as-cast
alloy and the upper boundary represents the conductivity of the
alloy based on varying process parameters and alloying agents.
[0026] The conductivity of a material is a strong driver in many
parameters of the material's electromagnetic signature (EMS).
Adjusting the conductivity of the base alloy for a through-alloy
coin or plated coin will impact the EMS of the coin and drive
towards unique signals that can be used to differentiate a coin
from other coins or slugs.
[0027] Blanks from two different representative zinc-manganese
alloys were produced and coined using a common token die. These
blanks were run through a coin sorting machine common to the
industry (ScanCoin 4000) and the data compared to other common base
or through alloy materials used in coinage production, such as
aluminum, bronze, cupronickel, stainless steel material and low
carbon steel. The output data is shown in FIG. 3. Differences from
other materials in only one of these variables or in the dimensions
of the coin is all that is required to consider a product unique.
Differences in more than one characteristic strengthens the
security of the coinage product. These zinc-manganese based alloys
can create unique electromagnetic signatures as compared to most
commonly used metals used in the coinage market. The signals
circled in the plots in FIG. 3 highlight the different EMS
signatures which can be used to differentiate coinage for security
purposes.
[0028] As noted above, a second application for these lower
conductivity alloys is within the electronics and fuse markets,
where the protective value of the component is often controlled by
conductivity and geometry, such as the amperage at the point of
planned failure in a low-voltage blade fuse. An electronic
component, such as a fuse, would be designed from a particular
alloy and then the geometry would be changed to control the final
resistance or conductivity value required. In the case of a fuse
used for low amperage control, the manufacturability is complicated
by the geometric cross-section required due to the inherent
conductivity of the standard zinc alloys used.
[0029] A schematic example of a fuse 10 is shown in FIG. 4 wherein
two electrical blade leads 12, 14 are connected by a thinner
cross-sectional area element 18. Element 18 and/or the entire fuse
10 can be constructed from any of the zinc-manganese alloys
described herein. Because of the higher electrical resistance of
the zinc-manganese alloys, the element 18 can be increased in
cross-sectional area to produce the same resistance as a smaller
conventional fuse element. Reducing conductivity of the fuse 10
and/or element 18 metal allows for an increase in cross-sectional
area of the element of a fuse to maintain an amperage rating which
can aide in manufacturing. Increasing the cross-sectional area of
the element can also result in increased reliability and
consistency of performance.
[0030] It will be appreciated by those skilled in the art that the
above reduced conductivity and unique electromagnetic signature
zinc alloy is merely representative of the many possible
embodiments of the invention and that the scope of the invention
should not be limited thereto, but instead should only be limited
according to the following claims.
* * * * *